Anti-Suit Injunction

An anti-suit injunction is an in personam remedy issued by a domestic court directing a litigant subject to its jurisdiction not to pursue parallel or vexatious proceedings before a foreign court or tribunal. The order does not bind the foreign court itself—doing so would breach comity—but operates on the party, who risks contempt if non-compliant.

The device is most developed in common law jurisdictions, particularly England and Wales, the United States, Singapore, and Hong Kong. English courts traditionally grant the remedy on two main grounds articulated in Société Nationale Industrielle Aérospatiale v Lee Kui Jak [1987] (Privy Council): where foreign proceedings are vexatious or oppressive, or where they breach an exclusive jurisdiction or arbitration clause. In the latter category, the threshold is lower; the applicant generally need only show a contractual right to be sued elsewhere.

Within the EU, the Court of Justice in Turner v Grovit (C-159/02, 2004) and West Tankers (C-185/07, 2009) held that anti-suit injunctions targeting proceedings in another Member State are incompatible with the Brussels Regulation regime, because they undermine mutual trust between courts. Post-Brexit, English courts have resumed issuing such injunctions against EU-seated proceedings where an English arbitration clause exists, as confirmed in cases such as Enka v Chubb [2020] UKSC 38.

Key features:

• In personam, not in rem — directed at the party, not the foreign forum.
• Discretionary — courts weigh comity, delay, and the foreign court's own competence.
• Often paired with arbitration — used to enforce London-, Singapore-, or New York-seated arbitration agreements.
• Enforced by contempt — fines, asset seizure, or imprisonment of company officers.

Civil law systems (France, Germany) generally view anti-suit injunctions with suspicion as an encroachment on sovereign judicial authority, and may refuse recognition or counter with anti-anti-suit injunctions, as seen in French and German patent litigation involving standard-essential patents in 2019–2021.