Federal Court of Australia

Greensill Bank AG v Insurance Australia Limited (Anti-Anti-Suit Injunction Application) [2025] FCA 1241

File number(s):

NSD 1216 of 2021

Judgment of:

THAWLEY J

Date of judgment:

10 October 2025

Catchwords:

PRIVATE INTERNATIONAL LAW – anti-anti-suit injunction – where there are eleven proceedings (the Greensill Proceedings) before this Court related to the purported issue of insurance policies and liability to pay amounts under those policies – where allegations of concurrent wrongdoing were raised against Marsh Ltd (an English company) and Marsh Pty Ltd (an Australian company) by respondents in the proceedings – where Greensill Bank AG foreshadowed joining Marsh Ltd to various proceedings – where Marsh Ltd and Marsh Pty Ltd applied to an English Court for an anti-suit injunction to restrain Greensill Bank AG from doing so – where basis of application was exclusive jurisdiction clauses contended to be contractually binding on Greensill Bank AG – where the English Court refused interim relief sought by Marsh Pty Ltd and mostly refused the interim anti-suit relief sought by Marsh Ltd – where Greensill Bank AG joined Marsh, and commenced proceedings against Marsh, in Australia – where the English Proceedings were then amended – where Greensill Bank AG seek interim anti-anti-suit relief to restrain Marsh Ltd and Marsh Pty Ltd from taking further steps in the English Proceedings – where the English Proceedings have been listed for final hearing for anti-suit relief – principles applicable to anti-suit and anti-anti-suit injunctions – whether basis for injunction in implied and/or equitable jurisdiction – whether balance of convenience favours the grant of injunction – held: anti-anti-suit relief granted

PRACTICE AND PROCEDURE – implied jurisdiction of the Federal Court to issue anti-anti-suit injunction – s 23 of the Federal Court of Australia Act 1976 (Cth) – where there is a basis for exercise of the Court’s implied jurisdiction in the tendency of English Proceedings to interfere with proceedings in this Court – principles of comity applicable in considering exercise of implied jurisdiction – where principles of comity do not require refusal of relief – balance of convenience favours grant of injunction

EQUITY – equitable jurisdiction of the Federal Court to issue anti-anti-suit injunction – where there is a basis for exercise of the Court’s equitable jurisdiction to prevent vexatious or oppressive foreign proceedings – not necessary to consider whether there is a basis for exercise of the Court’s equitable jurisdiction in aid of legal rights – where principles of comity do not require refusal of relief –balance of convenience favours grant of injunction

Legislation:

Australian Securities and Investments Commission Act 2001 (Cth)

Competition and Consumer Act 2010 (Cth) sch 2

Corporations Act 2001 (Cth)

Federal Court of Australia Act 1976 (Cth) s 23

Cases cited:

Ace Insurance Ltd v Moose Enterprise Pty Ltd [2009] NSWSC 724

Aggeliki Charis Compania Maritima SA v Pagnan SpA [1995] 1 Lloyd’s Rep 87

Airbus Industrie GIE v Patel [1999] 1 AC 119

Akai Pty Ltd v The People’s Insurance Co Ltd [1996] HCA 39; 188 CLR 418

Alkimos Shipping Co v Hind Lever Chemicals Corporation Ltd [2004] FCA 969

Allstate Life Insurance Co v Australia and New Zealand Banking Group Ltd (No 16) [1995] FCA 770

Apple Corps Ltd v Apple Computer Inc [1992] RPC 70

Australian Broadcasting Corp v O’Neill [2006] HCA 46; 227 CLR 57

Boost Tel Pty Ltd v Singtel Optus Pty Ltd [2023] FCA 213; 170 IPR 246

British Airways Board v Laker Airways Ltd [1985] AC 58

Carnival plc v Karpik (The Ruby Princess) [2022] FCAFC 149; 294 FCR 524

Continental Bank NA v Aeakos Compania Naviera SA [1994] 1 WLR 588

Credit Suisse Virtuoso SICA V-SIF v Insurance Australia Ltd (No 2) [2024] FCA 1308

Credit Suisse Virtuoso SICA V-SIF v Insurance Australia Ltd [2024] FCA 1193

CSR Ltd v Cigna Insurance Australia Ltd [1997] HCA 33; 189 CLR 345

Earl of Oxford’s Case (1615) 1 Ch Rep 1; 21 ER 485

Epic Games, Inc v Apple Inc (Stay Application) [2021] FCA 338; 151 ACSR 444

Harman v Secretary of State for the Home Department [1983] 1 AC 280

Hearne v Street [2008] HCA 36; 235 CLR 125

Herold v Seally (No 2) [2017] FCA 543

Hilton v Guyot 159 US 113 (1895)

Home Ice Cream v McNabb Technologies (No 2) [2018] FCA 1093

Jackson v Sterling Industries Ltd [1987] HCA 23; 162 CLR 612

Jones v Treasury Wine Estates Ltd [2016] FCAFC 59; 241 FCR 111

Kaepa, Inc v Achilles Corp 76 F 3d 624 (5th Cir 1996)

Karpik v Carnival plc (The Ruby Princess) (Stay Application) [2021] FCA 1082

Karpik v Carnival plc [2023] HCA 39

Marsh Ltd v Greensill Bank AG [2024] EWHC 3068 (Comm)

National Mutual Holdings Ply Ltd v Sentry Corporation [1989] FCA 274; 22 FCR 209

Oceanic Sun Line Special Shipping Co Inc v Fay [1988] HCA 32; 165 CLR 197

QBE Europe SA/NV v Generali Espana de Seguros y Reaseguros [2022] EWHC 2062 (Comm)

Rectron Australia BV v Lu [2014] NSWSC 1367

Ruswell’s Case (1616) 1 Rolle 193; 81 ER 425

Salkingstowe’s Case (1616) 1 Rolle 219; 81 ER 444

Smith Kline & French Laboratories Ltd v Bloch [1983] 1 WLR 730

Sterling Pharmaceuticals Pty Ltd v Boots Co (Australia) Pty Ltd [1992] FCA 71; 34 FCR 287

TS Production LLC v Drew Pictures Pty Ltd [2008] FCAFC 194; 172 FCR 433

Voth v Manildra Flour Mills Pty Ltd [1990] HCA 55; 171 CLR 538

Wigmans v AMP Ltd [2018] NSWSC 1118

Division:

General Division

Registry:

New South Wales

National Practice Area:

Commercial and Corporations

Sub-area:

Commercial Contracts, Banking, Finance and Insurance

Number of paragraphs:

180

Date of hearing:

1–2 September 2025

Counsel for Greensill Bank AG and Dr M Frege:

Ms V Whittaker SC with Mr C Tran and Mr K Sharma

Solicitor for Greensill Bank AG and Dr M Frege:

Quinn Emanuel Urquhart & Sullivan

Counsel for Marsh Ltd and Marsh Pty Ltd:

Mr M Darke SC with Mr C Colquhoun SC and Mr R A Jedrzejczyk

Solicitor for Marsh Ltd and Marsh Pty Ltd:

Johnson Winter Slattery

ORDERS

NSD 1216 of 2021

BETWEEN:

GREENSILL BANK AG

First Applicant

DR MICHAEL C FREGE IN HIS CAPACITY AS INSOLVENCY ADMINISTRATOR OF GREENSILL BANK AG

Second Applicant

AND:

INSURANCE AUSTRALIA LIMITED

First Respondent

BCC TRADE CREDIT PTY LTD

Second Respondent

GREG BRERETON (and others named in the Schedule)

Third Respondent

order made by:

THAWLEY J

DATE OF ORDER:

10 October 2025

THE COURT ORDERS THAT:

1.    Until final determination of the Applicants’ claims for relief against Marsh Limited and Marsh Pty Ltd in Federal Court proceedings NSD1216/2021, NSD173/2023, NSD174/2023, NSD175/2023, NSD177/2023, NSD602/2023 and NSD344/2025, Marsh Limited and Marsh Pty Ltd are restrained from taking any steps, either directly or indirectly, by themselves or through their subsidiaries or affiliates or agents, in the High Court of England and Wales or any other court (other than the Federal Court of Australia) to pursue, or seek to renew, their claims for relief in the High Court of England and Wales (Claim number CL-2024-000433), in relation to the letters of engagement between Greensill Capital (UK) Limited and Marsh Limited referred to in paragraph 4.a of the Amended Claim Form dated 16 April 2025.

Note:    Entry of orders is dealt with in Rule 39.32 of the Federal Court Rules 2011.

REASONS FOR JUDGMENT

THAWLEY J

OVERVIEW

1    These reasons relate to proceedings in this Court which arise out of the collapse in early 2021 of entities in the Greensill group. As at 2 July 2024, there were ten proceedings commenced by various applicants which were well progressed. Those proceedings are listed for hearing commencing on 3 August 2026. The facts are complex and involve many issues. The hearing is likely to take at least five months.

2    The applicants in six of the ten proceedings are Greensill Bank AG and the Insolvency Administrator, Dr Frege (collectively, GBAG). Marsh Ltd and Marsh Pty Ltd (collectively, Marsh) were not parties to those six proceedings, although they had been identified in the defences in those proceedings as concurrent wrongdoers. Marsh Ltd was a respondent in three proceedings brought by Credit Suisse (CS) entities. The CS entities claim damages and compensation from Marsh Ltd for misleading or deceptive conduct and in negligence.

3    Developments in the ten proceedings – in particular Marsh Ltd being a party in the three CS Proceedings – caused GBAG to consider it needed to join Marsh Ltd to the six GBAG Proceedings. This required GBAG to address a “Standstill Deed” to toll limitation periods it had with Marsh.

4    On 2 July 2024, GBAG gave Marsh 30 days’ notice of termination of the “Standstill Deed” and stated that it intended to join Marsh Ltd to the proceedings after the required 30-day notice period expired on 1 August 2024.

5    On 29 July 2024, Marsh Ltd and Marsh Pty Ltd commenced proceedings in the High Court of England and Wales. The relief Marsh sought included urgent ex parte interim anti-suit relief to prevent GBAG commencing proceedings against Marsh in Australia and to prevent it joining Marsh to the existing Australian proceedings. The English Proceedings concern a narrow range of issues, centrally whether GBAG and Marsh are bound by various choice of law and exclusive jurisdiction clauses in favour of the courts of England. The English Court granted Marsh Ltd an interim anti-suit injunction up until an inter partes hearing could be held. Marsh Pty Ltd was unsuccessful in obtaining any interim relief.

6    On 11 October 2024, this Court granted an ex parte interim anti-anti-suit injunction against Marsh Pty Ltd, amongst other things restraining Marsh Pty Ltd from continuing the English Proceedings. Marsh Pty Ltd’s claim in the English Proceedings was then stayed.

7    Marsh Pty Ltd was joined to the six GBAG Proceedings on 5 November 2024.

8    An inter partes hearing was held in the English Proceedings on 20 and 21 November 2024. With a confined exception, the English Court declined to continue the interim anti-suit relief which Marsh Ltd had been granted on an ex parte basis. The English Court was not satisfied to the required degree that there was an exclusive jurisdiction agreement which bound GBAG.

9    The English Proceedings have been listed for hearing from 27 April 2026 to 6 May 2026. Marsh Ltd’s claim for final anti-suit relief is one of the matters to be determined at that hearing. Marsh Pty Ltd’s claim would also be determined at that hearing if the anti-anti-suit injunction granted by this Court on 11 October 2024 is dissolved before the hearing, as Marsh contends it should be.

10    Marsh Ltd has now also been joined to the six GBAG Proceedings to which Marsh Pty Ltd was earlier joined. GBAG has also commenced a separate proceeding against Marsh Ltd and Marsh Pty Ltd such that there are now seven GBAG Proceedings and eleven Greensill Proceedings.

11    If Marsh obtains final anti-suit relief against GBAG in the English Proceedings, that would prevent GBAG from pursuing its claims against Marsh in the seven GBAG Proceedings.

12    It is in these circumstances that GBAG has applied for anti-anti-suit relief against Marsh. That application is the subject of these reasons. The issue is whether the Court should restrain Marsh from continuing the English Proceedings, or commencing new proceedings, in respect of the subject matter of the GBAG Proceedings. That injunction would operate until final determination of the claims made against Marsh in the seven GBAG Proceedings, including its claim for final injunctive relief. If granted, the existing anti-anti-suit injunction against Marsh Pty Ltd, which was made in a different Greensill Proceeding, would be superfluous and should be dissolved.

13    Apart from its statutory jurisdiction under s 23 of the Federal Court of Australia Act 1976 (Cth), the Court has an implied (inherent) and equitable jurisdiction to grant anti-anti-suit relief. In the circumstances of this case, the administration of justice is best served by granting the anti-anti-suit injunction sought by GBAG in exercise of both the Court’s implied and equitable jurisdiction.

14    Before addressing why that is so, it is convenient to summarise some of the relevant facts.

FACTUAL BACKGROUND

The Greensill Proceedings in this Court

15    The eleven proceedings before this Court (the Greensill Proceedings) are:

(a)    White Oak Proceeding: NSD1039 of 2021;

(b)    CS Proceedings (proceedings brought by Credit Suisse entities in respect of particular investing sub-funds):

(i)    NSD106 of 2022 (Catfoss Proceeding);

(ii)    NSD110 of 2022 (NMC Proceeding);

(iii)    NSD169 of 2023 (Credit Suisse Global Proceeding),

(c)    GBAG Proceedings:

(i)    NSD1216 of 2021 (EHG Proceeding);

(ii)    NSD173 of 2023 (Atlantic 57 Proceeding);

(iii)    NSD174 of 2023 (Bluestone Proceeding);

(iv)    NSD175 of 2023 (Liberty Commodities Proceeding);

(v)    NSD177 of 2023 (SIMEC Proceeding);

(vi)    NSD602 of 2023 (Liberty Delta Proceeding); and

(vii)    NSD344 of 2025 (APF Proceeding).

16    The most recent GBAG Proceeding – the APF Proceeding against Marsh – was commenced on 12 March 2025. Excluding the APF Proceeding, the parties refer to the proceedings set out above as the Indemnity Proceedings.

17    In the Indemnity Proceedings, the various applicants seek judgment against Insurance Australia Ltd (IAL) in respect of amounts alleged to be payable under insurance policies purportedly issued by BCC Trade Credit Pty Ltd (BCC) as authorised representative of IAL to GBAG and Greensill Capital Pty Ltd (in liquidation) (GCPL). The claimed losses total about AUD 7 billion and relate to debts owed to Greensill Capital (UK) Ltd (in administration) (GCUK) by its customers under various purported supply chain or accounts receivable finance facilities. Except for Dr Frege, the applicants in the Indemnity Proceedings invested in the finance programs set up by GCUK.

18    In addition to their claims for indemnity, the applicants also:

(a)    bring alternative claims against BCC and its former Head of Trade Credit, Mr Greg Brereton, seeking damages and compensation for misleading or deceptive conduct, false or misleading representations and breach of warranties of authority under the general law with respect to the authority to enter into the Policies;

(b)    claim that IAL and/or Tokio Marine & Nichido Fire Insurance Co Ltd, (TMNF) are responsible for BCC and Mr Brereton’s conduct as Australian financial services licensees under the Corporations Act 2001 (Cth) (Corporations Act);

(c)    in the Catfoss, Credit Suisse Global and White Oak Proceedings, bring claims against IAL, BCC, TMNF and its Australian managing agent, Tokio Marine Management (Australasia) Pty Ltd seeking damages and compensation for, amongst other claims, misleading or deceptive conduct and in negligence with respect to the alleged “post-July 2020 conduct”;

(d)    in the CS Proceedings, bring a claim against the insurance broker, Marsh Ltd, seeking damages and compensation for misleading or deceptive conduct and in negligence;

(e)    in the GBAG Proceedings, bring alternative claims against Marsh Ltd and Marsh Pty Ltd seeking damages and compensation for misleading or deceptive conduct and in negligence; and

(f)    in the CS and the GBAG Proceedings (excluding the APF Proceeding), bring alternative claims against IAL, seeking damages and compensation for misleading or deceptive conduct in respect of representations as to BCC’s authority arising from IAL’s conduct in respect of previous insurance policies purportedly issued by BCC as authorised representative of IAL to GBAG, GCUK and GCPL.

19    In the first six GBAG Proceedings, IAL (and others) allege that Marsh Ltd and Marsh Pty Ltd were concurrent wrongdoers.

GBAG foreshadows joining Marsh Ltd to the GBAG Proceedings

20    On 5 September 2023, GBAG, the Insolvency Administrator, Marsh Ltd and Marsh Pty Ltd entered into a “Standstill Deed” to toll limitation periods in respect of certain claims that GBAG and the Insolvency Administrator might have against Marsh Ltd and Marsh Pty Ltd, including claims relating to the Greensill Proceedings brought by GBAG and the Insolvency Administrator: Fox 1 at [19].

21    On 7 November 2023, amended statements of claim were filed in the CS Proceedings (in which Credit Suisse entities are the applicants), joining Marsh Ltd. Marsh Ltd filed defences on 6 March 2024.

22    On 2 July 2024, GBAG’s solicitors (Quinn Emanuel (QE)) wrote to Marsh’s solicitors (Holman Fenwick Willan LLP (HFW)) “providing 30 days notice of termination of the Standstill Period in respect of each of the Suspended Claims which are presently before the Federal Court (ie, the GBAG Proceedings)”: CB133 at [6]; Fox 1 at [20]. A termination notice was attached: CB135. The letter stated that GBAG was concerned that, because Marsh Ltd had been joined to the CS Proceedings and the issues overlapped with the issues in the GBAG Proceedings, if GBAG did not pursue relevant claims against Marsh Ltd at the same time, it might be prevented from bringing claims in future, either on the basis of an Anshun estoppel or because such proceedings might be considered to constitute an abuse of process. After stating that GBAG intended to join Marsh Ltd to the GBAG Proceedings, the letter stated that a draft of the amended pleadings (by which GBAG would seek to join Marsh Ltd to the GBAG Proceedings) would be provided as soon as possible. The letter also stated that GBAG would not agitate the claims until the expiration of the Standstill Period: CB134 at [8].

23    From this time, notwithstanding that proceedings against Marsh Pty Ltd had not been referred to in QE’s letter of 2 July 2024, Marsh Pty Ltd considered it was likely that GBAG would also seek to join it to the GBAG Proceedings. In addition to Marsh Ltd being a respondent in the CS Proceedings, Marsh had been told (at least by 26 July 2024) that GBAG would adopt IAL’s “concurrent wrongdoers” defence in the GBAG Proceedings which had named both Marsh Ltd and Marsh Pty Ltd: CB240 at [138]. The relevant statutory proportionate liability regimes operate such that, where a concurrent wrongdoer defence is raised, naming a person who is not an existing respondent, it is for the applicant to join the asserted concurrent wrongdoer if it wishes to protect itself from the possibility of under-recovery for any losses established.

Marsh seeks anti-suit relief against GBAG

24    On 29 July 2024, shortly before the 30-day notice period ended on 1 August 2024, Marsh commenced proceedings (English Proceedings) in the High Court of England and Wales (English Court) for urgent interim anti-suit relief and final anti-suit relief against the GBAG and Dr Frege (the Insolvency Administrator): CB136. In support of the application for interim relief, Marsh relied upon a ‘skeleton argument’ (around 42 pages of written submissions) and a witness statement from Marsh’s solicitor, Mr Foster: CB140; CB185.

25    Marsh observed that its application had to be heard before 1 August 2024 for the relief which it was seeking to be effective: CB143 at [5]. Mr Foster’s belief, based on advice he had received from Senior Counsel in Australia, was that, if GBAG was given notice of the application, then there was a substantial likelihood that GBAG would seek an anti-anti-suit injunction in Australia and a real prospect that, if such an application were made, an injunction would be granted: CB143 at [7]; CB188–9 at [10].

26    The material before the English Court made clear that Marsh was concerned that, if not restrained by an anti-suit injunction, GBAG would bring misleading and deceptive conduct claims against Marsh: CB145 at [10.7]; CB191 at [7(g)]. This was a reference to misleading and deceptive conduct claims under: the Corporations Act; the Australian Consumer Law, being Sch 2 to the Competition and Consumer Act 2010 (Cth); and the Australian Securities and Investments Commission Act 2001 (Cth). Apart from QE’s letter of 2 July 2024, Marsh’s concern arose because:

(a)    Marsh Ltd and Marsh Pty Ltd had been named in IAL’s “concurrent wrongdoers” defence which GBAG had said they would adopt in the GBAG Proceedings: CB240 at [138]–[143]; and

(b)    misleading and deceptive conduct claims had already been made against Marsh Ltd by the applicants in the CS Proceedings: CB150 at [27]; CB263D–F.

27    Marsh’s concerns included that, if GBAG were to bring claims in Australia against Marsh, such claims (some of which would not depend on proof of “fault”) would expose Marsh to a potential liability greater than that provided in relevant Terms of Engagement which contained limitations of liability of £7,500,000 and £10,000,000 CB241 at [143] to CB243 at [151]; CB286F–H.

28    On its ex parte application for an interim injunction in the English Proceedings, Marsh contended that GBAG was contractually bound by exclusive jurisdiction clauses contained in Letters of Engagement by which Marsh Ltd agreed to provide insurance brokerage services. The Letters of Engagement relied upon were (CB138):

(a)    Letters of Engagement addressed to, and signed by, GCUK, dated 3 March 2017, 27 March 2018, 27 March 2019 and 1 March 2020 (GCUK Engagements); and

(b)    a Letter of Engagement signed by GBAG, dated 18 April 2018, for a period of 12 months commencing on 1 March 2018 (GBAG Engagement).

29    The governing law and exclusive jurisdiction clauses in the Letters of Engagement were materially in the following form (CB2323):

The Engagement and any non-contractual obligations arising out of or in connection with it shall be governed by and construed in accordance with English law and any disputes related thereto shall be subject to the exclusive jurisdiction of the English courts.

30    Marsh contended before the English Court that the possibility of misleading and deceptive conduct claims being brought in Australia was not a reason for GBAG to be allowed to proceed there; rather, it was a reason why those claims should not be allowed to proceed in Australia and why the exclusive jurisdiction clause should be enforced: CB239 at [136(d)]; CB243 at [151]; CB286F–G.

The English Court grants ex parte relief to Marsh Ltd for a short period

31    On 30 July 2024, after an ex parte hearing before Cockerill J in the English Court, Marsh Ltd obtained orders for interim anti-suit relief: CB297. The English Court did not grant relief to Marsh Pty Ltd, but the English Interim Orders granted liberty to Marsh Pty Ltd to re-apply for such relief in the event of a material change in circumstances: Fox 1 at [24]; CB292C–D; CB300 at [4].

32    The question of whether the interim anti-suit relief was to be continued, pending the hearing of the English Proceedings for final injunctive relief, was to be determined at an inter partes return date hearing, which was later fixed for 20 and 21 November 2024: Fox 1 at [25].

This Court grants ex parte anti-anti-suit relief in relation to Marsh Pty Ltd only

33    By an interlocutory application dated 3 October 2024, filed in the Catfoss Proceeding, GBAG applied for various orders against Marsh Ltd. The orders sought included ex parte interim anti-anti-suit orders. The interlocutory application dated 3 October 2024 was formally filed on 14 October 2024 and amended on 18 October 2024.

34    The ex parte component of the interlocutory application was heard by Moshinsky J on 10 October 2024. His Honour made orders on 11 October 2024 granting relief against Marsh Pty Ltd and refusing relief against Marsh Ltd: Credit Suisse Virtuoso SICA V-SIF v Insurance Australia Ltd [2024] FCA 1193 (Credit Suisse No 1).

35    In his Honour’s reasons for granting the relief, Moshinsky J recorded (at [12] and [25]) that one of GBAG’s principal contentions was that Marsh, in seeking (and preparing to seek) ex parte interim anti-suit relief before the English Court, had used documents and information that were disclosed by GBAG to Marsh Ltd by way of discovery in the CS Proceedings such that Marsh Ltd and Marsh Pty Ltd had breached the implied undertaking referred to in Harman v Secretary of State for the Home Department [1983] 1 AC 280 and Hearne v Street [2008] HCA 36; 235 CLR 125 at [96] (Hayne, Heydon and Crennan JJ). The interlocutory application dated 3 October 2024 sought, by way of final relief, a declaration to the effect that Marsh Ltd and Marsh Pty Ltd had breached the implied undertaking: CB351 at [13]; CB435 at [13].

36    After the ex parte interim anti-anti-suit injunction had been granted against Marsh Pty Ltd, it consented to the continuation of the injunction against it on a without admissions basis: T23.8. That interim injunction continues. No hearing has been listed in respect of final relief against Marsh Pty Ltd.

GBAG joins Marsh Pty Ltd to the GBAG Proceedings

37    On 4 November 2024, GBAG was granted leave to join Marsh Pty Ltd to the six GBAG Proceedings then on foot: CB445 at [26]. Marsh Pty Ltd was joined the next day.

38    On 11 November 2024, Moshinsky J heard argument on whether Marsh breached the Hearne v Street obligation. On 12 November 2024, the Court:

(a)    declared that Marsh Ltd and Marsh Pty Ltd had breached the Hearne v Street obligation; and

(b)    ordered that, from the date of the order, Marsh Ltd and Marsh Pty Ltd be released from the Hearne v Street obligation for the purpose of the English Proceedings: Credit Suisse Virtuoso SICA V-SIF v Insurance Australia Ltd (No 2) [2024] FCA 1308.

39    Shortly before the hearing of the present application, the Full Court heard an appeal brought by Marsh from the orders made on 12 November 2024. Judgment is reserved. The parties agreed that nothing in the present application turned on the result of the appeal. I have treated the declaration of breach of the Hearne v Street obligation – the making of which is challenged on appeal – as irrelevant to this application.

The English Court mostly refuses Marsh Ltd interim anti-suit relief

40    On 20 and 21 November 2024, Deputy High Court Judge Simon Colton KC heard argument on whether the English Interim Orders should continue pending the hearing of the English Proceedings for final relief: Fox 1 at [37]; Marsh Ltd v Greensill Bank AG [2024] EWHC 3068 (Comm).

41    The parties proceeded before the English Court on the basis that the relevant principles which governed the grant of anti-suit relief in a wholly contractual context (see CB154 at [37]) were those summarised by Foxton J in QBE Europe SA/NV v Generali Espana de Seguros y Reaseguros [2022] EWHC 2062 (Comm) at [10] and [11]: [2024] EWHC 3068 at [23], [46]. These principles include (relevantly for present purposes) that: (i) the injunction applicant must establish with a “high degree of probability” that there is an exclusive jurisdiction agreement which governs the dispute in question; and (ii) if the applicant shows the matter in (i), the court will ordinarily exercise its discretion to restrain the pursuit of proceedings brought in breach of the exclusive jurisdiction clause unless the defendant shows “strong reasons” to refuse the relief.

42    On 11 December 2024, Deputy Judge Colton KC made orders enjoining GBAG and the Insolvency Administrator from bringing claims against Marsh Ltd (but not Marsh Pty Ltd) in respect of the GBAG Engagement (dated 18 April 2018). Marsh was wholly unsuccessful in relation to the GCUK Engagements dated 3 March 2017, 27 March 2018, 27 March 2019 and 1 March 2020: CB692 at [1].

43    In concluding that Marsh Ltd had not shown that there was a “high degree of probability” that there was an exclusive jurisdiction agreement binding on GBAG, apart from in respect of the GBAG Engagement, his Honour applied a test which was “close” to the summary judgment test, namely that the Court should not grant anti-suit relief unless it considers that the defendant would have no real prospect of defeating the application at trial, taking into account the evidence that could reasonably be expected to be available at trial: [2024] EWHC 3068 at [55].

44    The result of the orders made by the English Court on 11 December 2024 was that GBAG and the Insolvency Administrator were enjoined from bringing claims against Marsh Ltd in Australia in respect of the GBAG Engagement but not in respect of the GCUK Engagements. There has never been an injunction preventing GBAG from bringing claims against Marsh Pty Ltd in Australia and that has remained the position.

45    On 6 January 2025, GBAG applied to the English Court of Appeal for permission to appeal from the orders made by the English Court. Permission was refused on 7 March 2025: CB1121.

GBAG joins Marsh Ltd to the GBAG Proceedings and commences fresh proceedings

46    On 12 February 2025, QE provided to HFW draft originating applications and statements of claim, seeking to join Marsh Ltd to the GBAG Proceedings: CB744; T32.8–12.

47    In the eleventh and most recently commenced proceeding – the APF Proceeding, filed on 12 March 2025 – GBAG and the Insolvency Administrator bring claims for damages against Marsh for misleading or deceptive conduct and in negligence. In the APF Proceeding, unlike in the Indemnity Proceedings, GBAG does not bring a claim of indemnity against IAL, nor alternative claims against BCC, Mr Brereton or TMNF.

48    On 14 March 2025, the Court granted leave for Marsh Ltd to be joined to the GBAG Proceedings: CB803 at [1]. Marsh Ltd did not oppose its joinder but has at all times “reserved its rights in the English proceedings”. By this, Marsh means to make clear that it contends that its joinder to the GBAG Proceedings is in breach of exclusive jurisdiction clauses: CB998, 1944, 1948 and 1952. Marsh Ltd was joined to the six GBAG Proceedings on 17 March 2025. The claims made against Marsh Ltd do not rely on the GBAG Engagement dated 18 April 2018 in respect of which the English Court has granted anti-suit relief.

49    In summary, in the GBAG Proceedings, GBAG and the Insolvency Administrator allege that:

(a)    Marsh provided broking services to GBAG, as part of which they made representations about the authority of BCC and/or Mr Brereton as well as about the validity of insurance policies (and endorsements) providing coverage to GBAG; and

(b)    In the event that those representations were contrary to the true position, Marsh engaged in misleading or deceptive conduct contrary to the provisions of the statutes mentioned earlier.

Marsh amends its claim in the English Proceedings

50    On 4 April 2025, HFW informed QE that Marsh proposed to amend the Claim Form in the English Proceedings to include: (i) a mandatory injunction; and (ii) damages: CB819. These amendments were stated to be in response to GBAG: (a) bringing claims against Marsh Ltd in the APF Proceeding; and (b) joining Marsh Ltd to the six GBAG Proceedings: CB821 at [3(a)]. Marsh proposed to amend [6] of the claim as follows (CB824):

In the premises, the Claimants [Marsh], alternatively C1 [Marsh Ltd], seek an interim and a final prohibitory injunction under s 37(1) of the Senior Courts Act 1981, on a contractual basis (C1 in respect of both Claimants against Dl [GBAG]) and/or a benefit/burden basis (C1 in respect of both Claimants against D2 [the Insolvency Administrator]; C2 against both Defendants) and/or to prevent vexatious/oppressive conduct (C2 against both Defendants), restraining the Defendants from wrongfully commencing proceedings against C1 and/or C2 in Australia; and C1 seeks a final mandatory injunction requiring Ds [GBAG and the Insolvency Administrator] to stay the Australian claims now brought against it, alternatively damages for breach of the GCUK Letters of Engagement, to be assessed, and interest thereon under s 35A Senior Courts Act 1981. The Claimants further seek their costs, to be assessed.

51    Marsh also proposed to amend the claim to include a further GCUK Letter of Engagement, dated 18 April 2016: CB824 at [4(a)].

52    I interpolate that GBAG argued on this application that the claim brought by Marsh in the English Proceedings had become “redundant” before these amendments by reason of the limited relief which had been granted by the English Court: T36.26–38; T56.33.

53    The claim was not entirely “redundant”. In its unamended claim, Marsh Ltd’s claim for a “final prohibitory injunction” in respect of all of the relevant Letters of Engagement remained for determination. On the other hand, the claim was close to pointless without the introduction of new claims to reflect the changed circumstances. Because Marsh had largely (but not entirely) failed in its application for an interim “prohibitory injunction”, and claims against Marsh had been commenced in Australia, Marsh introduced new primary claims, namely: a claim for a mandatory injunction to require GBAG to stay the Australian proceedings; and an alternative claim for damages.

54    In its skeleton argument for a case management conference scheduled for 11 April 2025, Marsh explained the amendments in the following way (CB2541):

23.1    First, whereas the claim was originally for a prohibitory injunction, the primary claim must now be for a mandatory injunction directed at the Australian actions which are underway (although a prohibitory injunction is still sought, in order to guard against any other claims);

23.2    Secondly, whereas the original claim for a prohibitory injunction would have prevented any breach of contract taking place, and so would have prevented any damages being caused by such a breach, [GBAG and the Insolvency Administrator] have now (if [Marsh Ltd’s] case is accepted at trial) acted in breach of contract and begun to cause damage to [Marsh Ltd]. Accordingly, [Marsh Ltd] is entitled to damages for breach of the exclusive jurisdiction clause, to be assessed in due course.

55    GBAG did not oppose the amendments to the Claim Form: CB874 at [2.1]; CB2542 at [27].

56    At the case management conference, Marsh sought an unopposed order that Marsh Pty Ltd’s claim be stayed: CB2537 at [5.1]. The seeking of such an order gave effect to the interim anti-anti-suit injunction ordered by Moshinsky J.

57    Marsh’s skeleton argument observed that the “damages now claimed will only be capable of being fully quantified when the Australian proceedings have run their course” and that Marsh therefore proposed an order that the trial address all issues, including liability to damages, but not the quantification of damages for the contended breaches of the exclusive jurisdiction clauses: CB2542 at [28.1]; see also: CB1147 at T25.16–23.

58    At the case management conference, Marsh sought a hearing date as early as possible before the Australian trial was to commence: CB1161 at T81.4–8. Orders were made on 11 April 2025 granting leave to amend the Claim Form: CB2179 at [2]. It was amended on 16 April 2025 substantially in accordance with what had been foreshadowed: CB1193. Orders were also made on 11 April 2025 granting leave to file Amended Particulars of Claim, which were subsequently filed: CB2179 at [2]; CB1196. The English Proceedings have been fixed for trial from 27 April 2026 to 6 May 2026: CB2242.

GBAG applies for anti-anti-suit relief

59    By an interlocutory application dated 23 April 2025, GBAG applied for anti-anti-suit relief: CB3. The first part of this application was heard ex parte by Moshinsky J on 24 April 2025: CB1721. The orders made included an order that Marsh Ltd be restrained from taking steps in England to interfere with GBAG having its interlocutory application heard and determined by this Court: CB14 at [4]. His Honour delivered concise ex tempore reasons, explaining that the orders were to preserve the status quo until an inter partes hearing: CB1726.

60    The interlocutory application dated 23 April 2025 was amended on 12 June 2025 and is the subject of these reasons.

The English Court lists the English Proceedings for hearing

61    On 21 May 2025, orders were made by the English Court giving effect to what had been decided at the case management conference on 11 April 2025: CB2178. Marsh Pty Ltd’s claims in the English Proceedings were formally stayed: CB2179 at [1]. The orders also set out the various steps to be taken in preparation for trial, including orders for ‘disclosure’ by 31 October 2025 and exchange of signed witness statements by 16 January 2026: CB2180–1. Order 15 was to the effect that the trial would address all issues save for the issue of quantum of damage for breach of the exclusive jurisdiction clause, if liability in that respect were established at trial: CB2180.

GBAG amends its pleadings to seek final anti-anti-suit relief

62    On 12 June 2025, GBAG filed further amended originating applications and statements of claim in the GBAG Proceedings. This was done because of a question raised by Moshinsky J at the ex parte hearing on 24 April 2025 about whether the interlocutory application was the correct process for seeking final relief: T40.33; CB1725–6.

63    During submissions on this application, the parties referred to the Fifth Amended Originating Application (5AOA EHG) and Sixth Amended Statement of Claim (6ASOC EHG) in the EHG Proceeding: CB2552 and CB2559. The 5AOA EHG (and the amended originating applications in each of the GBAG proceedings) added a claim for final anti-anti-suit injunctive relief against Marsh. The 6ASOC EHG introduced a claim under the heading “Marsh Injunctive Relief”, comprising [203AE]–[203BG]: CB 2724. At the risk of oversimplification, those paragraphs allege that the purpose and effect of the English Proceedings was to seek to prevent GBAG from obtaining relief against Marsh and to avoid or negative the consequences should such relief be granted – see, in particular: [203AW]–[203BB].

64    Marsh filed its defences in the GBAG Proceedings in June and July 2025. A number of procedural orders concerning Marsh have been made, including orders for discovery (now completed) and amendments to expert questions (the Insurance Broking Questions).

65    Marsh is required to serve lay evidence by 21 November 2025. Marsh has not sought a stay of the claims made against them in Australia by GBAG. All eleven Greensill Proceedings are listed for hearing commencing on 3 August 2026.

DISPOSITION

66    Marsh submitted that considerations of comity should – of themselves – lead to GBAG’s application being dismissed: T86.12–5. Marsh therefore addressed comity first and suggested that the remaining issues would not arise if its submissions on comity were accepted: T87.10–15.

67    At least in this case, what comity might require is better assessed after examining whether there is a basis for exercising the Court’s jurisdiction to grant an anti-anti-suit injunction. For the reasons given below, considerations of comity:

(a)    require that anti-suit injunctions – whether in the Court’s implied or equitable jurisdiction – only be issued with caution;

(b)    are weighty in this case, as they generally would be in any case in which an anti-suit injunction is contemplated; and

(c)    do not, in the circumstances, lead to the result that the implied or equitable jurisdiction to grant an injunction should not be exercised.

68    Before turning to whether there is a proper basis for exercising the Court’s implied or equitable jurisdiction, it is convenient to say something briefly about available remedies where there are overlapping domestic and overseas proceedings.

Stays and anti-suit injunctions where domestic and foreign proceedings overlap

69    The question whether a dispute as to legal rights should be litigated domestically or overseas may be resolved by one court staying its proceedings in favour of the other, or by a court granting an anti-suit injunction restraining a person amenable to its jurisdiction from commencing or continuing the foreign proceedings: CSR Ltd v Cigna Insurance Australia Ltd [1997] HCA 33; 189 CLR 345 at 389–90.

70    Steps short of an injunction may be appropriate, such as the proceedings in an Australian court being held in temporary abeyance pending resolution of certain issues in the overseas proceedings – see: Sterling Pharmaceuticals Pty Ltd v Boots Co (Australia) Pty Ltd [1992] FCA 71; 34 FCR 287 at 292 (Lockhart J), referred to by the High Court in CSR at 390. Other intermediate remedies may be appropriate, moulded to the circumstances: Herold v Seally (No 2) [2017] FCA 543 at [34(2)] (Bromwich J).

71    The remedies of a domestic stay, and of an anti-suit injunction in relation to foreign proceedings, are not governed by the same principles: CSR at 390.

72    In CSR, the High Court held that the Supreme Court of New South Wales had erred in failing to order a stay of NSW proceedings brought by CSR’s insurers and in granting an anti-suit injunction in respect of CSR’s proceedings in the United States: at 402–3. The NSW proceedings were held to be oppressive in the relevant sense because CSR had advantageous statutory remedies available to it in the US which had no equivalent in NSW and the insurers’ central purpose in instituting the NSW proceedings was to prevent the continuation of the US proceedings: at 402.

The Court has an implied and equitable jurisdiction to grant anti-anti-suit relief

73    An anti-suit injunction is an in personam remedy enjoining a party from commencing or continuing proceedings in a foreign court: Credit Suisse No 1 at [37]; Jones v Treasury Wine Estates Ltd [2016] FCAFC 59; 241 FCR 111 at [21].

74    An anti-anti-suit injunction is also an in personam remedy. It involves an order that a party not seek anti-suit injunctive relief in a foreign court in relation to proceedings in the domestic court: Credit Suisse No 1 at [37], referring to Davies M, Bell A, Brereton P, Douglas M, Nyghs Conflict of Laws in Australia (10th ed, LexisNexis, 2020) at [9.17].

75    A party could seek an anti-anti-anti-suit injunction to enjoin a party from seeking anti-anti-suit relief – see: Allstate Life Insurance Co v Australia and New Zealand Banking Group Ltd (No 16) [1995] FCA 770 (Lindgren J); Wigmans v AMP Ltd [2018] NSWSC 1118 at [11], [16] (Ward CJ).

76    An anti-suit injunction and an anti-anti-suit injunction may be granted in exercise of the Court’s implied (or inherent) jurisdiction or its equitable jurisdiction: CSR at 392. The Federal Court’s power to grant injunctions, including anti-suit injunctions, derives from its implied and equitable jurisdiction and s 23 of the Federal Court of Australia Act 1976 (Cth) – see: Jackson v Sterling Industries Ltd [1987] HCA 23; 162 CLR 612 at 618 (Wilson and Dawson JJ).

There is a basis to exercise the Court’s implied jurisdiction

Principles

77    An anti-suit injunction may be granted in exercise of the implied jurisdiction to protect the continuation of proceedings regularly commenced in the Court when the administration of justice so demands: CSR at 392; Credit Suisse No 1 at [40]; Herold at [34(7)].

78    The High Court in CSR observed that the power to stay domestic proceedings is an aspect of the Court’s implied power to prevent its processes being used to bring about injustice. The High Court observed that “[t]he counterpart of a court’s power to prevent its processes being abused is its [inherent or implied] power to protect the integrity of those processes once set in motion”, by issuing an anti-suit injunction: CSR at 391.

79    The High Court in CSR gave examples of when the Court’s implied jurisdiction might be exercised to grant an anti-suit injunction, stressing that the examples were neither “confined” nor “restricted to defined and closed categories”: CSR at 391–2. The examples included an injunction to restrain a person in foreign proceedings from seeking to obtain the sole benefit of foreign assets where a bankrupt estate is being administered in Australia. The High Court also referred to National Mutual Holdings Pty Ltd v Sentry Corp [1989] FCA 274; 22 FCR 209 at 232, in which Gummow J observed that a court may grant an injunction to restrain a person from commencing or continuing foreign proceedings if the foreign proceedings interfere, or have a tendency to interfere, with proceedings pending in the domestic court.

The basis for exercise of jurisdiction

80    Leaving questions of comity (and other issues) aside, is there a basis for exercise of the Court’s implied jurisdiction?

81    On 2 July 2024, GBAG informed Marsh that GBAG would seek to join Marsh Ltd to the first six GBAG Proceedings after expiry of the 30 days’ notice period under the Standstill Deed: CB133. GBAG stated that it would provide draft pleadings to Marsh Ltd as soon as possible, presumably with a view to attempting to secure Marsh Ltd’s consent to being joined to the proceedings: CB134 at [8].

82    Marsh commenced the English Proceedings on 30 July 2024, shortly before the 30 days’ notice period expired on 1 August 2024 and obtained an ex parte interim anti-suit injunction against Marsh Ltd only: CB297.

83    The English Proceedings were commenced because Marsh knew that Marsh was likely to be joined by GBAG to the first six GBAG Proceedings and wished to prevent that occurring by obtaining anti-suit relief. Marsh Ltd was already a respondent in the CS Proceedings in which claims for damages were brought against it for negligence and misleading or deceptive conduct. Further, the concurrent wrongdoer defences raised by IAL, BCC and Mr Brereton in the first six GBAG Proceedings identified Marsh as concurrent wrongdoers. This defence (if successful) would operate to reduce any judgment against IAL, BCC and Mr Brereton which could be given in favour of GBAG by reference to the proportionate responsibility of (amongst others) Marsh. It was almost inevitable that GBAG would seek to join Marsh in those circumstances. This was a reason why Marsh sought the relief it did from the English Court: CB240 at [138].

84    Marsh Pty Ltd was wholly unsuccessful in obtaining anti-suit relief in the English Proceedings. Marsh Ltd was largely unsuccessful in obtaining anti-suit relief.

85    As mentioned earlier:

(a)    Marsh Pty Ltd was joined to the first six GBAG Proceedings on 5 November 2024;

(b)    on 12 March 2025, GBAG commenced the seventh GBAG Proceeding against Marsh Ltd and Marsh Pty Ltd; and

(c)    on 17 March 2025, Marsh Ltd was joined to the first six GBAG Proceedings.

86    On each of these occasions, the jurisdiction of this Court with respect to Marsh was regularly invoked. At each of these times, there was no relevant anti-suit injunction which prevented the commencement of the proceeding against Marsh or the joinder of the relevant Marsh party to the relevant proceeding. If final anti-suit relief is granted in the English Proceedings, in the form of an in personam anti-suit order preventing GBAG from continuing the existing proceedings so far as they concern Marsh, that will interfere with the GBAG Proceedings.

87    After Marsh was joined to the GBAG Proceedings and the APF Proceeding was commenced, Marsh amended its Claim Form in the English Proceedings to introduce a new claim for a mandatory injunction which would require GBAG to apply to stay the GBAG Proceedings (so far as those proceedings concern Marsh). If that relief were to be granted, it would also interfere with GBAG’s proceedings in this Court.

88    It follows that the English Proceedings have a tendency to interfere with proceedings in this Court. Accordingly, there is a basis for this Court to exercise its implied jurisdiction to protect proceedings regularly before it, by granting anti-anti-suit relief.

89    Whether the Court should grant the relief depends on additional matters considered below, after first addressing some of Marsh’s submissions concerning implied jurisdiction.

Marsh’s submissions

90    Marsh submitted that the present case was not one which engaged the Court’s implied jurisdiction to protect its own processes: T87.19–38. Apart from its reference to various authorities, Marsh made three interrelated points in this regard.

91    First, Marsh submitted that the relief Marsh seeks in the English Proceedings would only be granted if it were found that GBAG was a party to the GCUK Letters of Engagement and as such had agreed: (i) that the law governing its contractual arrangements with Marsh, and any non-contractual obligations arising out of or in connection with those engagements, would be the law of England; and (ii) to submit all disputes relating to those contractual engagements and non-contractual obligations to the exclusive jurisdiction of the English courts. Marsh submitted that:

(a)    if an anti-anti-suit injunction is issued to protect this Court’s jurisdiction to determine the statutory misleading conduct claims, that is to treat the misleading conduct provisions of the various statutes as mandatory laws of the Australian forum;

(b)    the various statutes prohibiting misleading conduct, on which GBAG relies, are not mandatory laws of the Australian forum; and

(c)    there is no suggestion made by GBAG that the choice of law and exclusive jurisdiction clause itself was used in an attempt to evade the operation of misleading and deceptive conduct laws of Australia: T88.45.

92    Secondly, and closely related to the first submission, Marsh submitted that the injunctive relief Marsh sought in the English Proceedings will not be granted if GBAG establishes that there are “strong reasons”’ for not enforcing the exclusive jurisdiction clause, even if, as a matter of contract, GBAG is bound by it: T93.36–9. That argument is reflected in GBAG’s amended defence in the English Proceedings: CB2258 at [49].

93    It is convenient to address these two submissions before the third.

94    It is sufficient for the exercise of the implied jurisdiction that the English Proceedings have the tendency to interfere with the determination of the claims regularly brought against Marsh in the GBAG Proceedings. The exercise of jurisdiction on this basis does not depend on a conclusion that the statutory misleading conduct provisions are mandatory laws of Australia.

95    It is neither necessary nor appropriate to decide for the purposes of this application whether the statutory misleading conduct provisions are “mandatory” laws of the forum in the sense that they are applied by Australian courts regardless of where the events occurred and even if the proper law of the contract is not Australia. The parties referred in this regard to the following authorities which are relevant to the topic in differing, and not necessarily consistent, ways: Home Ice Cream v McNabb Technologies (No 2) [2018] FCA 1093 (Greenwood ACJ); Epic Games, Inc v Apple Inc (Stay Application) [2021] FCA 338; 151 ACSR 444 at [18]–[19] (Perram J); Karpik v Carnival plc (The Ruby Princess) (Stay Application) [2021] FCA 1082 at [123] (Stewart J); Carnival plc v Karpik (The Ruby Princess) [2022] FCAFC 149; 294 FCR 524 at [324]–[346] (Derrington J); and Karpik v Carnival plc [2023] HCA 39.

96    In circumstances where it is not necessary to do so, and the relevant underlying facts were not addressed by the parties, the question whether the statutory misleading conduct provisions are “mandatory” in the relevant sense is not one which should be determined on incomplete facts.

97    The fact that GBAG can raise various arguments in the English Proceedings as constituting “strong reasons” for not enforcing any of the exclusive jurisdiction clauses found to be contractually binding on GBAG does not deny a basis for anti-anti-suit relief and is a matter I have also taken into account in considering questions of comity and balance of convenience.

98    Thirdly, Marsh submitted (T95–6) that:

(a)    although the High Court in CSR said that the implied power was not restricted to defined and closed categories, the present case was not of a kind that the High Court contemplated in respect of the implied power;

(b)    when anti-suit relief is sought in the implied jurisdiction, the Court need not consider whether it is an appropriate forum for the resolution of the issue between the parties, because it is the only court with any interest in the matter, referring to CSR at 398;

(c)    this Court is not the only court with any interest in the resolution of the question whether GBAG is bound by the exclusive jurisdiction clauses in favour of the English courts, because the English Court has a proper interest in the resolution of that issue;

(d)    the implied power is properly engaged only in cases where the processes of the Australian court are threatened in such a way that it can fairly be said that the interests of no other court are at play.

99    In CSR at 398, the High Court observed that it is only the domestic court which is the appropriate forum to determine the question whether the domestic court’s proceedings or processes warranted protection by anti-suit injunction. That is a confined proposition. It stated (emphasis added):

In cases where anti-suit injunctions are sought to protect the proceedings or processes of a court, no question arises whether that court is an appropriate forum for the resolution of that issue: it is the only court with any interest in the matter.

100    That sentence occurs in the context of the High Court accepting that, generally, a Court must first consider whether it is an appropriate forum before granting an anti-suit injunction.

101    Contrary to Marsh’s submission, the High Court in CSR at 398 did not state or suggest that the implied jurisdiction is properly engaged only in cases where the processes of an Australian court are threatened in such a way that it can fairly be said that the interests of no other court are at play. There is no doubt that the English Court has a proper interest in the resolution of the question whether GBAG is bound by the exclusive jurisdiction clauses in the Letters of Engagement signed by GCUK. There is nothing in CSR which contemplates that an anti-anti-suit injunction cannot be issued in exercise of the implied jurisdiction simply because a foreign court is also an appropriate forum for resolution of an issue relevant in the domestic proceedings.

There is also a basis to exercise the Court’s equitable jurisdiction

Principles

102    In contrast to the implied jurisdiction of a court to protect its processes once regularly invoked, the equitable jurisdiction to grant an anti-suit injunction derives from the historical practice of the English Court of Chancery making orders restraining parties from pursuing claims in the English courts of common law, or preventing enforcement of common law judgments – see, for example: Earl of Oxfords Case (1615) 1 Ch Rep 1; 21 ER 485. This practice led to decisional conflict between the Court of Chancery (Lord Ellesmere, being the Lord Chancellor) and the King’s Bench (Sir Edward Coke, being the Chief Justice) – see, for example: Ruswells Case (1616) 1 Rolle 193; 81 ER 425; Salkingstowes Case (1616) 1 Rolle 219; 81 ER 444.

103    This conflict was ultimately famously resolved by King James I declaring that, in such cases, equity would prevail.

104    Later practice saw Chancery make orders, in appropriate cases, restraining parties from pursuing claims outside the United Kingdom – see: Airbus Industrie GIE v Patel [1999] 1 AC 119 at 133B–C (Lord Goff).

105    This history has led to modern courts making orders, in the exercise of equitable jurisdiction, in restraint of unconscionable conduct or the unconscientious exercise of legal rights: CSR at 392. An injunction may be granted in the exercise of the Court’s equitable jurisdiction in restraint of proceedings no matter where they are brought: CSR at 392.

106    The power to order an injunction in the exercise of the Court’s equitable jurisdiction is not confined to the examples found in the decided cases. The limits of the power are determined by the dictates of equity and good conscience (CSR at 394) and the remedy is discretionary. However, the High Court in CSR referred to two categories of cases in which the power has been exercised.

107    First, the equitable jurisdiction to restrain unconscionable conduct may be exercised in aid of legal rights, for example in aid of:

(a)    an agreement not to sue or not continue proceedings – see: British Airways Board v Laker Airways Ltd [1985] AC 58 at 81C–D (Lord Diplock); Apple Corps Ltd v Apple Computer Inc [1992] RPC 70 at 77 (Hoffmann J); Rectron Australia BV v Lu [2014] NSWSC 1367 at [57] (Lindsay J);

(b)    an agreement to sue or not to sue in a particular jurisdiction – see: Continental Bank NA v Aeakos Compania Naviera SA [1994] 1 WLR 588 at 596D–E (Brown P, Steyn and Kennedy LJJ); Ace Insurance Ltd v Moose Enterprise Pty Ltd [2009] NSWSC 724 at [78] (Brereton J);

(c)    an arbitration agreement – see: Aggeliki Charis Compania Maritima SA v Pagnan SpA [1995] 1 Lloyd’s Rep 87 at 96 (Millett LJ) (The Angelic Grace); Alkimos Shipping Co v Hind Lever Chemicals Corporation Ltd [2004] FCA 969 at [25] (Allsop J).

108    Secondly, apart from the exercise of equitable jurisdiction in aid of legal rights, an injunction may be granted in the exercise of equitable jurisdiction in respect of proceedings in a foreign court, which are vexatious or oppressive according to the principles of equity: CSR at 393.

109    It is convenient first to address the exercise of the equitable jurisdiction in relation to vexatious or oppressive proceedings, before considering whether there is a basis for exercise of the equitable jurisdiction in aid of legal rights.

Exercise of equitable jurisdiction in relation to vexatious or oppressive proceedings

110    In addition to what has been said above, it is relevant to refer to four matters in relation to the exercise of equitable jurisdiction in relation to vexatious or oppressive proceedings.

111    First, the terms vexatious or oppressive were used in CSR (see at 401–2) in the sense in which those terms were used in Voth v Manildra Flour Mills Pty Ltd [1990] HCA 55; 171 CLR 538 at 555 (concerning the power to grant a stay), where the High Court (Mason CJ, Deane, Dawson and Gaudron JJ) stated:

‘Oppressive’ should, in this context, be understood as meaning seriously and unfairly burdensome, prejudicial or damaging while ‘vexatious’ should be understood as meaning productive of serious and unjustified trouble and harassment.

112    Secondly, although the same terms are used, applications for a grant of a stay and for an anti-suit injunctions are governed by different principles and raise different issues.

113    The relevant question on a stay application is whether the domestic proceeding is vexatious or oppressive. A stay of Australian proceedings in favour of foreign proceedings is only granted if the Australian court is a “clearly inappropriate forum”, a test derived from the judgment of Deane J in Oceanic Sun Line Special Shipping Co Inc v Fay [1988] HCA 32; 165 CLR 197: Voth; CSR at 390–1. At least in cases where the issues in the domestic and foreign proceedings are the same, the test focusses attention more on the consequences of the proceeding rather than the conduct of the applicant in bringing the proceeding.

114    Because the issues involved in the domestic and foreign proceedings in CSR were different, but arose out of the same sub-stratum of fact, the question was not whether the Australian court was a clearly inappropriate forum for the litigation of the issues involved in the Australian proceedings, but whether, having regard to the controversy as a whole, the Australian proceedings were vexatious or oppressive in the Voth sense: CSR at 400. In granting a stay of the Australian proceedings, the High Court concluded at 401:

Proceedings which are brought for the dominant purpose of preventing another party from pursuing remedies available in the courts of another country and not available in this country are “seriously and unfairly ... prejudicial [and] damaging”. They are, thus, oppressive in the Voth sense of that word.

115    The relevant question on an application for an anti-suit injunction is whether the foreign proceeding is vexatious or oppressive. The equitable nature of the jurisdiction, and the in personam nature of an application for an anti-suit injunction, require focus on the conduct of the party sought to be enjoined and the consequences of that conduct. It follows that proceedings might be found to be “oppressive” in the relevant sense, for the purposes of granting an anti-suit injunction, if the proceedings are brought for the dominant purpose of preventing another party from pursuing remedies available in another court.

116    Thirdly, if proceedings have been commenced in Australia, and complete relief is available in those proceedings, then it may be vexatious to commence proceedings in a foreign jurisdiction. In CSR at 393, the High Court stated:

Thus, it was said in Carron Iron Co v Maclaren that “[w]here [there is] ... pending a litigation here, in which complete relief may be had, [and] a party to the suit institutes proceedings abroad, the Court of Chancery in general considers that act as a vexatious harassing of the opposite party, and restrains the foreign proceedings”.

117    The mere co-existence of proceedings in different countries does not constitute vexation or oppression: CSR at 393. The “foreign proceedings are to be viewed as vexatious or oppressive only if there is nothing which can be gained by them over and above what may be gained in local proceedings”: CSR at 393. To put the matter a different way, foreign proceedings are vexatious or oppressive only where there is “complete correspondence between the proceedings”: CSR at 393; see also Credit Suisse No 1 at [43]; Herold at [34(11)] and [43]; TS Production LLC v Drew Pictures Pty Ltd [2008] FCAFC 194; 172 FCR 433 at [55] and [59] (Gordon J, Stone J agreeing).

118    Foreign proceedings commenced in response to domestic proceedings would be even more vexatious if complete relief (CSR at 393) is available in the domestic proceedings, but the relevant relief is not available in the foreign proceedings.

119    The commencement of foreign proceedings in response to pending Australian proceedings might not be vexatious or oppressive if there is some juridical or legitimate advantage to be gained in the foreign court that is not available in the domestic court.

120    Fourthly, it should be observed that inefficiencies and additional costs are generally insufficient of themselves for a proceeding to be relevantly vexatious or oppressive: TS Production at [57]. Likewise, proceedings are not relevantly oppressive only because it would be plainly desirable to have overlapping issues resolved in one place at one time: TS Production at [58]. An applicant for an anti-suit injunction must demonstrate that the further prosecution of the foreign proceedings would be “productive of serious and unjustified trouble and harassment” or “severely and unfairly burdensome, prejudicial or damaging”: Oceanic Sun Line at 247; CSR at 401; TS Production at [56].

121    Leaving questions of comity (and other issues) aside, is there a basis for exercise of the Court’s equitable jurisdiction in relation to relevantly vexatious or oppressive proceedings?

122    The English Proceedings were commenced because GBAG informed Marsh Ltd that it would be joined to the GBAG Proceedings after the expiry of the 30 days’ notice period. The English Proceedings were commenced for the purpose of preventing future claims: GBAG from commencing proceedings against Marsh or joining Marsh to the existing proceedings.

123    Marsh characterises its purpose as one of seeking to enforce choice of law and exclusive jurisdiction clauses in contracts signed by GCUK which it asserts are contractually binding on GBAG. Expressing Marsh’s purpose in that way does not detract from the fact that the purpose of the commencement of the English Proceedings was to prevent future claims being made against Marsh in the existing GBAG Proceedings and in new proceedings.

124    The purpose of Marsh’s amendment to the Claim Form in April 2025, in particular to require GBAG to stay the GBAG Proceedings – made after the APF Proceeding was commenced and after Marsh had been joined to the other six GBAG Proceedings – is one of seeking to disrupt this Court from determining then existing claims regularly brought by GBAG.

125    Again, expressing Marsh’s purpose as seeking to enforce various choice of law and exclusive jurisdiction clauses in contracts signed by GCUK, allegedly binding on GBAG, does not detract from the fact that the principal objective behind the amendments was preventing the existing claims against Marsh being determined in this Court.

126    Marsh submitted that the English Proceedings were not like the proceedings in CSR which had no purpose other than to prevent CSR from pursuing remedies available in the US proceedings, but not in the NSW proceedings: T113.29–35.

127    Accepting that submission as correct, the principles in CSR do not prevent the exercise of the power to grant anti-suit relief in the Court’s equitable jurisdiction merely because the party to be enjoined has an arguable basis for the relief which the party seeks in the foreign jurisdiction, or has a purpose which can be characterised as seeking to pursue or enforce that arguable claim for relief.

128    Quite apart from questions of purpose, this Court’s jurisdiction has been regularly engaged with respect to GBAG’s claims against Marsh in the GBAG Proceedings, in circumstances where complete relief is available in Australia, but not available if GBAG were forced to pursue its claims in England.

129    Marsh submitted that there was not a “complete correspondence” between the English and Australian proceedings in the sense described in CSR at 393 because Marsh’s claim for injunctive relief in the English Proceedings does not arise in Australia: RS[70(f)].

130    It is true that the Marsh parties’ claim for injunctive relief in the English Proceeding does not arise for determination in Australia. However, there are two difficulties with the submission. First, where an anti-anti-suit injunction is sought, it can always be said that the respondent’s claim for injunctive (anti-suit) relief does not arise for determination in the Court considering whether to grant anti-anti-suit relief. Secondly, whilst Marsh’s claim for injunctive relief does not arise in the GBAG Proceedings, the underlying facts and issues the subject of the English Proceedings will arise for consideration. Marsh can (and presumably will) rely on its choice of law and exclusive jurisdiction arguments in the GBAG Proceedings, albeit the arguments will occur in the context of determining a broader range of issues. So-called “complete correspondence” is not necessarily denied by the fact that the issues raised in the foreign jurisdiction form only a subset of the issues which arise in the domestic proceedings.

131    I do not consider Marsh’s submission that GBAG did not contest jurisdiction in the English Proceedings to be of significant weight. If GBAG had contested jurisdiction, Marsh would have had to show a “good arguable case” that GBAG was bound by an exclusive jurisdiction clause. This could potentially have been satisfied at an interlocutory stage by showing a plausible (albeit contested) evidential basis for the proposition that GBAG was bound by an exclusive jurisdiction clause – see: Foster 1 at [17]. As noted above, in order to obtain the anti-suit relief it sought, Marsh had to establish the existence of an exclusive jurisdiction clause to the “high degree of probability” standard.

132    It might also be observed that, whilst Marsh has made clear during its participation in proceedings before this Court that it “reserves its rights”, it has also “consented” to jurisdiction: T63.25.

133    Marsh submitted that the fact that GBAG commenced statutory misleading conduct claims against Marsh in Australia after the English Proceedings had been commenced does not make the English Proceedings vexatious or oppressive. Marsh referred in this regard to the High Court’s observation in CSR at 395 that foreign proceedings do not become vexatious or oppressive if “the party against whom they are brought later commences proceedings with respect to the same subject matter in this country”: RS[72].

134    That proposition may be accepted as far as it goes. However, the fact that a party secured a hearing and succeeded in obtaining anti-suit relief before the other party commenced foreshadowed proceedings or obtained anti-suit relief, is not necessarily determinative of whether it is appropriate to grant anti-anti-suit relief, albeit those matters are relevant and important, particularly on questions of comity. The English Proceedings brought by Marsh were regularly instituted shortly before the expiry of the 30 days’ notice given by GBAG, but they were instituted first only because GBAG notified Marsh that they would wait before joining them to the GBAG Proceedings. The amendments to the Claim Form in the English Proceedings, which included the claim for a mandatory injunction requiring GBAG to seek a stay of the GBAG Proceedings, were introduced after Marsh had been joined to the Australian proceedings and after fresh proceedings against Marsh had commenced. These matters are relevant to the exercise of equitable jurisdiction.

135    The English Proceedings are vexatious and oppressive in the particular sense in which those words are used in this context. They were instituted, amended and are being continued for the purpose of preventing GBAG from making statutory misleading conduct claims and having those claims determined. Further, complete relief is only available in the Australian proceedings. As a matter of substance, all the issues in the English Proceedings, and more, can be raised in the GBAG Proceedings.

Exercise of equitable jurisdiction in aid of legal rights

136    Leaving questions of comity (and other issues) aside, is there a basis for exercise of the Court’s equitable jurisdiction in aid of legal rights?

137    GBAG contended that the Marsh parties should be restrained from seeking to enforce the exclusive jurisdiction clause in England because “foreign proceedings that seek to give effect to a contractual exclusive jurisdiction clause undermine” the statutory misleading conduct provisions: AS[68]–[70]. This submission was not, or not clearly, directed to a contention that the Court should exercise its equitable jurisdiction in aid of legal rights.

138    It is arguable that a “mandatory” domestic law might give rise to a legal right that justifies the restraint of foreign proceedings, even when that mandatory law is in conflict with an exclusive jurisdiction clause in favour of a foreign court – see the discussion in Akai Pty Ltd v The Peoples Insurance Co Ltd [1996] HCA 39; 188 CLR 418 at 446–8 (Toohey, Gaudron and Gummow JJ).

139    In circumstances where it is not necessary to do so, and relevant underlying facts were not addressed by the parties, it is not appropriate to address the questions whether: (a) the statutory misleading conduct provisions are “mandatory” in the relevant sense; or (b) the Court should exercise its equitable jurisdiction in aid of legal rights on this basis.

This Court is not a clearly inappropriate forum

140    Where an anti-suit injunction is sought on equitable grounds, and the proceedings in different forums raise the same issues, the Australian court should be satisfied that it is not a clearly inappropriate forum in which to determine the dispute. If it concludes it is a “clearly inappropriate forum”, it must refuse the anti-suit injunction: CSR at 397–8; Herold at [34(4)] and [40].

141    Marsh properly accepted, for the purposes of this application only, that this Court is not a clearly inappropriate forum: RS[68].

142    Given this Court is not a clearly inappropriate forum, the question becomes whether to: (a) require the applicant to seek a stay or dismissal of the foreign proceedings; or (b) grant an anti-suit injunction: CSR at 397–8.

143    GBAG has not applied for a stay of the English Proceedings because it received advice from King’s Counsel that there was no reasonable basis to seek a stay: CB2100 at [9]; 2103 at [9]; CB2115. The fact that GBAG has not sought a stay in these circumstances is not a bar to the relief it seeks – see CSR at 398; RS[70(e)]. GBAG should not be required first to seek a stay or dismissal of the English Proceedings.

Considerations of comity do not require refusal of relief

144    Considerations of comity require “that the power to grant injunctions in restraint of foreign proceedings should be exercised with caution … whether the injunction is sought in the exercise of the inherent or equitable jurisdiction”: CSR at 396. In CSR at 396, the High Court referred to the statement of the Supreme Court of the United States in Hilton v Guyot 159 US 113 (1895) at 163–4:

‘Comity’, in the legal sense, is neither a matter of absolute obligation, on the one hand, nor of mere courtesy and good will, upon the other. But it is the recognition which one nation allows within its territory to the legislative, executive or judicial acts of another nation, having due regard both to international duty and convenience, and to the rights of its own citizens or of other persons who are under the protection of its laws.

145    Comity requires respect for judicial proceedings in a foreign jurisdiction, and a considered response, but it does not require reflex genuflection or total deference on each occasion that a court must decide whether to enjoin a foreign action – see: TS Production at [60]; Kaepa, Inc v Achilles Corp 76 F 3d 624 (5th Cir 1996); Smith Kline & French Laboratories Ltd v Bloch [1983] 1 WLR 730. How the principles of comity apply will depend on the circumstances.

146    GBAG submitted that considerations of comity are of no real weight when the application for anti-anti-suit relief is based on the implied jurisdiction of the Court to protect its own processes: T21.30; T52.16–9; T55.45–56.2. In support of this submission, GBAG referred to the High Court’s statement in CSR at 398 in a passage principally concerned with whether the Court should consider whether it is an appropriate forum before granting an anti-suit injunction:

In cases where anti-suit injunctions are sought to protect the proceedings or processes of a court, no question arises whether that court is an appropriate forum for the resolution of that issue: it is the only court with any interest in the matter. Subject to that consideration, the appellants are correct in their contention that, before granting an interlocutory anti-suit injunction, an Australian court should consider whether it is an appropriate forum, in the Voth sense, for the resolution of the matter in issue or, if there be a difference, the matter advanced in support of the injunction.

147    The point made in that passage is not about comity. The confined point made in the first sentence is that the domestic court is an appropriate forum for determining whether it should protect its own processes by issuing an anti-suit injunction. This observation was made in the context of affirming that a court should ordinarily consider whether it is an appropriate forum, in the Voth sense, before issuing an anti-suit injunction. The confined proposition was that a court does not need to consider whether it is a clearly inappropriate forum to determine whether it should protect its own processes, because it is the only court directly interested in that matter. It does not follow from this narrow statement of the obvious that considerations of comity are of no real weight, or that they have a reduced role to play, where the anti-suit injunction is sought in the exercise of the implied jurisdiction. The High Court expressly stated in CSR at 396 that considerations of comity require that anti-suit injunctions only be issued with caution “whether the injunction is sought in the exercise of the inherent or equitable jurisdiction”.

148    Marsh submitted that the relief sought by GBAG, if granted, is contrary to the principles of comity because it would directly and substantially interfere with the English Court’s processes by requiring Marsh Ltd to breach orders of the English Court: T71–2. Marsh submitted that, if granted, the relief “expects” or “require[s]” the English Court to set its own orders aside or compels Marsh to breach those orders if not set aside: T72.12; T72.35.

149    If relief is granted, it would “interfere with the processes” of the English Court in that it would require Marsh Ltd to take appropriate steps to stop pursuing its claims for relief in the English Court: CSR at 395. This could be done, for example, by Marsh Ltd seeking orders staying the English Proceedings until further order. This is what occurred in the English Proceedings to give effect to the anti-anti-suit injunction made against Marsh Pty Ltd by Moshinsky J at a time when Marsh Pty Ltd had failed in obtaining anti-suit relief against GBAG in the English Proceedings. The taking of such steps is the natural consequence of the exercise of the power to enjoin a party from continuing foreign proceedings.

150    Marsh submitted that the same (or equivalent) considerations of comity which informed the decision of Moshinsky J on 11 October 2024 to refuse anti-anti-suit relief in relation to Marsh Ltd provided a reason – of itself – to refuse such relief on this (assertedly weaker) application.

151    In his reasons for refusing the application for interim anti-anti-suit relief against Marsh Ltd, Moshinsky J observed that “considerations of comity constitute a strong discretionary consideration against making the interim orders that are sought by GBAG and the Insolvency Administrator”: Credit Suisse Virtuoso No 1 at [54]. His Honour observed that the orders GBAG sought – in particular, paragraphs 4(c) and 15(a) of the interlocutory application – would “interfere with the Interim Orders that have been made by the English Court … contrary to principles of comity”: at [56]. A primary concern was that the interference “would be direct and substantial, in that the anti-anti-suit injunction sought in paragraph 15(a) … (if granted) would in practical terms negate the effect of the existing anti-suit injunction” granted by the English Court: at [57].

152    The principles of comity did not lead Moshinsky J to refuse the interim relief sought by GBAG against Marsh Pty Ltd. The position with respect to Marsh Pty Ltd was seen to be different because the English Court had not issued an anti-suit injunction against GBAG in relation to Marsh Pty Ltd: Credit Suisse Virtuoso No 1 at [60]. The anti-anti-suit relief granted to GBAG by Moshinsky J in relation to Marsh Pty Ltd interfered with the English Court’s processes to a degree. The English Court had reserved liberty for Marsh Pty Ltd to re-apply for anti-suit relief and Marsh Pty Ltd’s claim for final relief remained to be determined. Accordingly, the anti-anti-suit injunction ordered against Marsh Pty Ltd interfered with the English Proceedings, in that it was contrary to the liberty to apply and, as a practical matter, required Marsh Pty Ltd to seek a stay of its claim in the English Proceedings.

153    The differences between the situation which prevailed when Moshinsky J considered the question of comity and the position now include:

(a)    First, leaving aside the anti-suit injunction related to the one GBAG Engagement, there are no relevant extant anti-suit orders made by the English Court such that the anti-anti-suit injunction sought is not in conflict with any anti-suit relief granted by the English Court.

(b)    Secondly, when the ex parte application was heard by Moshinsky J on 10 October 2024, GBAG had not commenced proceedings against Marsh or joined Marsh to the existing proceedings. This has now occurred.

154    The fact that it was inappropriate in the circumstances which prevailed as at 10 October 2024 to grant anti-anti-suit relief – in relation to Marsh Ltd only – says little about the present situation.

155    In my view, the principles of comity are not such as to require the Court to refuse anti-anti-suit relief in the circumstances as they are now. Justice Moshinsky’s principal concern was that the anti-anti-suit injunction would, if granted: (a) negate the effect of the existing anti-suit injunction which Marsh Ltd had obtained on an interim ex parte basis; and (b) prevent Marsh Ltd from seeking a continuation of the interim orders at the contested hearing scheduled for 20 and 21 November 2024. That situation no longer prevails.

156    Principles of comity are important. The granting of an anti-anti-suit injunction would interfere with the English Proceedings, but the injunction would not negate the effect of any extant anti-suit injunction issued by the English Court. Where an anti-suit injunction is granted to restrain pending foreign proceedings, the anti-suit injunction will always interfere with the processes of the foreign court because the domestic injunction restrains the party from further prosecuting the proceedings in the foreign court. Principles of comity do not require the relief always to be refused. Comity requires proper respect for the processes of the foreign court and a considered response in the particular circumstances. If the English Proceedings were to continue and, if Marsh were successful, the English Court’s order against GBAG would interfere with the processes of this Court.

157    Principles of comity do not require the relief to be refused in the circumstances of this case.

158    In the context of addressing comity, Marsh criticised GBAG for not seeking anti-anti-suit relief in December 2024 when Marsh’s anti-suit injunctive relief was not continued in the English Proceedings, noting that GBAG’s application was not brought until 23 April 2025: T72. Marsh submitted that the English Proceedings continued with GBAG’s active participation (for example on 11 April 2025) and the proceedings were listed for hearing without opposition.

159    In context, the delay is not of a kind which warrants refusing the relief sought. The English Court of Appeal did not refuse GBAG’s application for permission to appeal the English Court’s orders until 7 March 2025. Further, GBAG was occupied in commencing the APF Proceeding against Marsh and joining Marsh Ltd to the GBAG Proceedings.

GBAG has a prima facie case and the balance of convenience favours granting relief

160    Given that this Court is not a clearly inappropriate forum, and that GBAG should not be required to seek a stay or dismissal of the foreign proceedings, the remaining issue is that which ordinarily applies with respect to interlocutory relief: CSR at 398.

161    The issue is whether: (a) there is a serious issue to be tried (CSR at 398) in the sense of there being a prima facie case (Australian Broadcasting Corp v ONeill [2006] HCA 46; 227 CLR 57 at [65]); and (b) the balance of convenience favours the grant of relief: CSR at 398. Those two issues are interrelated in that the strength of one can affect the weight to be given to the other: Boost Tel Pty Ltd v Singtel Optus Pty Ltd [2023] FCA 213; 170 IPR 246 at [12].

162    As to the first question – a serious issue to be tried – Marsh did not submit that this was not satisfied or that the prima facie case was so weak that it had a material effect on questions of balance of convenience.

163    As to the second question – balance of convenience – Marsh made five principal submissions. It is convenient to address balance of convenience by reference to Marsh’s submissions and to deal with the first two of Marsh’s submissions together.

164    First, Marsh submitted that the effect of an injunction would be to foreclose Marsh Ltd’s claim for injunctive relief in the English Proceedings: RS[84]. If Marsh Ltd establishes that GBAG is bound by the GCUK Letters of Engagement, an anti-anti-suit injunction would have deprived it of the opportunity to enforce the exclusive jurisdiction clause and have GBAG’s claims heard in England. Marsh submitted that the Court should proceed on the basis that the anti-anti-suit injunction sought by GBAG is, in substance, final rather than interlocutory relief.

165    Marsh Ltd would also incur significant costs in defending GBAG’s claims in Australia, which might otherwise be avoided.

166    Secondly, Marsh submitted that the procedural consequences of granting anti-anti-suit relief would render the English Proceedings practically inutile: RS[85]. The injunction would operate until final determination of GBAG’s claims for final injunctive relief in the Australian proceedings. Marsh submitted that: given the anticipated length and complexity of the hearing, judgment can be expected to take considerable time; if there is an appeal, it is unlikely to be heard before late 2028, with judgment unlikely before the first half of 2029; there may be a further appeal to the High Court; the result is that it may be years before the English Proceedings could be revived, by which point it may have no real utility.

167    If anti-anti-suit relief is not granted against Marsh Ltd: the English Proceeding would be heard in April 2026. It is likely that the outcome in the English Proceeding will be known shortly before the trial in Australia is due to commence. The following considerations arise:

(a)    If the outcome in the English Proceedings is favourable to Marsh Ltd, then GBAG would be precluded from prosecuting statutory claims for damages and compensation against Marsh Ltd in Australia. It is not clear whether an appeal in the English courts would be able to be heard and determined before the trial in Australia commences. It was common ground that misleading conduct claims could not be brought by GBAG in England. This outcome would cause significant prejudice to GBAG, particularly in circumstances where any judgment it might obtain against other respondents might be reduced in accordance with relevant statutory proportionate liability regimes.

(b)    If the outcome in the English Proceeding is unfavourable to Marsh Ltd, then GBAG would have suffered no relevant prejudice by the decision not to grant an anti-anti-suit injunction.

168    The observations made immediately above potentially also apply in respect of the claims made against Marsh Pty Ltd in the GBAG Proceedings. Marsh submitted that, if GBAG’s application for anti-anti-suit relief in this proceeding (made against both Marsh Ltd and Marsh Pty Ltd) is dismissed, the interim anti-suit injunction ordered by Moshinsky J against Marsh Pty Ltd in the Catfoss Proceeding should also be discharged: RS[91]. If that submission is accepted, then Marsh Pty Ltd would no longer be restrained from pursuing its claims in the English Proceedings.

169    If anti-anti-suit relief against Marsh is granted by this Court: the parties to the English Proceeding would presumably seek a stay of the whole of the English Proceedings until the GBAG Proceedings are finally determined. The following considerations arise:

(a)    If GBAG is unsuccessful in obtaining final injunctive relief at the Australian hearing: Marsh could resume the English Proceeding with any loss to be addressed as part of its claim for damages in that proceeding.

(b)    If GBAG is successful in obtaining final injunctive relief at the Australian hearing: Marsh will have suffered significant prejudice in that it would have lost the opportunity of avoiding such a result by obtaining final anti-suit relief against GBAG in the English Proceeding. It is relevant that Marsh can raise the choice of law and exclusive jurisdiction clauses in the GBAG Proceedings. It is far from clear at this interlocutory stage that, if the parties are found to have agreed to have their commercial contractual relationship governed exclusively by English law and English courts, that agreement would be relevantly undone by statute.

170    As to the costs of the GBAG Proceedings: GBAG and the Insolvency Administrator have agreed to an initial tranche of security for costs in the amount of $5 million. Marsh’s solicitors have estimated that Marsh’s GST-exclusive costs of litigating the GBAG Proceedings will likely be in the range of $15 to $20 million for a trial of four months: CB2105; CB2375. It is likely that further security for costs will be agreed or ordered if shown to be appropriate. The costs incurred by Marsh in the English Proceedings, which involve more confined issues than those in the GBAG Proceedings, and which are comparatively low, are not a significant factor in the context of litigation of this scale. It is also relevant that Marsh Ltd will have to participate in the Greensill Proceedings in any event because it is a respondent in the CS Proceedings.

171    It is also convenient to deal with Marsh’s third and fourth submissions together.

172    Marsh’s third submission was that there was no evidence that GBAG – which has been in insolvency administration since March 2021 – has the capacity to pay any award of damages: RS[86]. In addition to Marsh’s costs of defending the GBAG Proceedings, if Marsh is held to be liable to GBAG, the quantum of any damages claim arising from GBAG’s breaches of the exclusive jurisdiction may run into the billions of dollars. Marsh submitted that it is, accordingly, no answer for GBAG to contend that any prejudice occasioned by an anti-anti-suit injunction may be cured by Marsh’s claim for damages.

173    Fourthly, Marsh submitted that, for the reasons given in relation to its third submission, whilst GBAG has proffered the usual undertaking as to damages, the undertaking does not appear to be of any substance: RS[87].

174    If GBAG is successful against Marsh, but unsuccessful in obtaining final injunctive relief and the issue raised by Marsh arises, then appropriate steps are likely to be able to be devised to ensure that any amount which Marsh is ordered to pay is appropriately quarantined until its claim for damages is determined in the English Proceedings. It follows from this, and the fact that GBAG and the Insolvency Administrator have capacity to give security for costs, that the usual undertaking as to damages is of substance.

175    Finally, Marsh submitted that the Court should give no weight to GBAG’s submission that it has no reasonable prospect of obtaining a stay of the English Proceedings: RS[88]. It noted that, by the time that GBAG filed the present application on 24 April 2025, it had already submitted to the English Court’s jurisdiction to determine Marsh’s claims and had been participating actively in the English Proceeding for some nine months. If GBAG had little prospect of obtaining a stay at that point in time, that was a situation entirely of its own making.

176    The import of these submissions has been addressed earlier.

177    Weighing these competing considerations together, and accepting that there is much to be said both ways, I consider the balance of convenience supports granting the relief sought by GBAG and the Insolvency Administrator.

CONCLUSION

178    The order sought is in the following terms (CB11):

Until final determination of the Applicants’ claims for relief against Marsh Limited and Marsh Pty Ltd in Federal Court proceedings NSD1216/2021, NSD173/2023, NSD174/2023, NSD175/2023, NSD177/2023, NSD602/2023 and NSD344/2025, Marsh Limited and Marsh Pty Ltd are restrained from taking any steps, either directly or indirectly, by themselves or through their subsidiaries or affiliates or agents, in the High Court of England and Wales or any other court (other than the Federal Court of Australia) to pursue, or seek to renew, their claims for relief in the High Court of England and Wales (Claim number CL-2024-000433), in relation to the letters of engagement between Greensill Capital (UK) Limited and Marsh Limited referred to in paragraph 4.a of the Amended Claim Form dated 16 April 2025.

179    Paragraph 4.a of the Amended Claim Form refers to the GCUK Engagements.

180    An order in those terms should be made. As mentioned, making this order would render the existing interim anti-anti-suit injunction in the Catfoss Proceeding superfluous.

I certify that the preceding one hundred and eighty (180) numbered paragraphs are a true copy of the Reasons for Judgment of the Honourable Justice Thawley.

Associate:

Dated: 10 October 2025

SCHEDULE OF PARTIES

NSD 1216 of 2021

Respondents

Fourth Respondent:

TOKIO MARINE & NICHIDO FIRE INSURANCE CO LTD

Fifth Respondent:

MARSH PTY LTD

Sixth Respondent:

MARSH LIMITED