First of a kind: High Court grants injunction restraining enforcement of an English Court judgment

Recent High Court judgment clarifies the scope of the English court's powers to grant anti-enforcement injunctions and the applicable legal test for granting anti-suit injunctions

 In the recent decision of Federal Government of Nigeria and another v Williams,¹ the English High Court granted an interim anti-enforcement injunction (AEI) restraining a party from pursuing the enforcement of an English judgment in New York. The decision is significant for the following reasons:

1. It is the first reported instance of an English court granting an AEI restraining the enforcement of an English court judgment – confirming that the power of the English courts to grant AEIs is not limited to foreign judgments.
2. It provides guidance that, when an order for an interim anti-suit injunction (ASI) would be decisive of the forum in which the substantive dispute will be tried, an applicant must demonstrate a 'high probability' of successfully obtaining a final ASI on the merits, rather than the lower threshold test of a 'serious issue to be tried.'
3. It underlines the value in taking steps to address potential issues of comity in foreign proceedings when seeking AEI relief and considers how such issues apply when dealing with enforcement of an English court judgment. 

Background

This recent judgment is the latest development in an ongoing dispute between Dr Williams and the Federal Government of Nigeria (FGN) and the Attorney General of the FGN (AG). The case traces back to an undercover operation in Nigeria in 1986 to identify breaches of Nigerian foreign exchange controls. As a result of this operation, Dr Williams was criminally convicted and sentenced to 10 years' imprisonment and fined, but was later pardoned in 1993. Dr Williams has since pursued a number of claims in the English courts against various Nigerian parties seeking to recover alleged losses incurred as a result of the operation. In 2016, Dr Williams commenced proceedings against the FGN and the AG. In default of acknowledgement of service, on 9 November 2018 he obtained a default judgment for c.US$15 million against FGN and the AG (the Default Judgment). 

In 2020, the FGN and AG applied to set aside the Default Judgment on the basis that it was procured by fraud, alleging that Dr Williams relied on falsified documents and made false representations in support of his application for the Default Judgment. The set aside application has not reached final determination. In the meantime, in 2023, Dr Williams commenced proceedings in the US District Court for the Southern District of New York (the New York Court) to recognise and enforce the Default Judgment. The FGN and AG subsequently made an application in England for an AEI restraining Dr Williams from proceeding with the enforcement of the Default Judgment in the New York Court on the grounds that such enforcement would be vexatious and oppressive. The AEI was granted by Mr Justice Henshaw on 11 July 2025, and the written reasons for making this order were delivered in his judgment of 26 August 2025. 

Granting AEIs to restrain the enforcement of English judgments 

AEIs are a form of equitable relief that may be granted when the Court is satisfied that it is just and convenient to do so.³ However, they are rarely granted, as applicants must displace the serious concerns of comity and/or delay which such orders engage.⁴ They are also less common than ASIs, which are sought at an earlier procedural stage to restrain the commencement or continuation of proceedings. 

Despite an absence of case law considering whether AEIs may be granted in relation to English court judgments, the Court held that there was 'no principled reason' why AEIs should be limited to restraining the enforcement of foreign judgments.⁵ AEIs are an important protective mechanism in proceedings involving judgments obtained fraudulently. In these circumstances the Court considered it appropriate to grant an AEI in relation to an English court judgment in order to 'protect the integrity of the English court's own processes' and to 'prevent a risk of its own judgment being used as an instrument of fraud'.⁶

Applicable test for ASIs

Whilst the judgment concerned an application for an AEI, Henshaw J also provided guidance on the test to be met for a successful ASI application brought on the grounds that the foreign proceedings would be vexatious and oppressive. Departing from his previous dicta remarks in Investcom Global Ltd v PLC Investments Ltd [2024],⁷ Henshaw J averred that the applicant will generally need to demonstrate 'a high probability that it will succeed in establishing its case for a final anti-suit injunction at trial',⁸ rather than  the lower threshold test 'requiring demonstration of a serious issue to be tried' ⁹ (the American Cyanamid test). Henshaw J considered that this more stringent test will generally be more appropriate on the basis that this type of interim order 'will often be decisive of the issue by determining, in practice, where the substantive dispute is tried'.¹⁰ However, in circumstances where the interim order will not be decisive and is only sought on a temporary basis, then it may still be appropriate for the court to apply the American Cyanamid test. 

Comity 

This case also illustrates the procedural steps that parties can take in foreign proceedings to assuage an English court's concern that granting an ASI or AEI would offend principles of comity, which is often a challenging obstacle to overcome when seeking ASI or AEI relief. In particular, the New York Court ordered that the New York action be stayed until determination of the AEI application. The Order also stipulated that the parties will abide by the decision rendered by the English court in relation to the AEI and that if an AEI was granted, the parties agreed that no further proceedings will occur in New York unless the AEI is vacated.¹¹ Henshaw J observed that such deference to English courts illustrated that the New York Court was 'acting consistently with comity'.¹²

The Court also recognised that, as the AEI sought related to an English judgment, some of the comity sensitivities that would ordinarily be assessed in an AEI application were 'less likely to be of concern'.¹³

1.[2025] EWHC 2217 (Comm) (Williams).
2.Williams [18].
3.s37(1) Senior Courts Act 1981; Google v Tsargrad [2025] EWHC 94 (Comm) [57].
4.Google v Tsargrad [2025] EWHC 94 (Comm) [82].
5.Williams [15].
6.Williams [23].
7.Investcom Global Ltd v PLC Investments Ltd [2024] EWHC 2505 (Comm) [81].
8.Williams [18].
9.Williams [17].
10.Williams [19].
11.Williams [6] to [10].
12.Williams [23].
13.Wiliams [15].