In West Tankers Inc (Respondents) v RAS Riunione Adriatica di Sicurta SpA and others (Appellants) [2007] UKHL 4, the main question facing the House of Lords was whether a Member State court may grant an injunction against a person bound by an arbitration agreement to restrain him from commencing or prosecuting proceedings in the courts of another Member State which has jurisdiction to entertain the proceedings under the Brussels Regulation.

The dispute involves the Respondents, West Tankers, defending two sets of proceedings. The charterers commenced an arbitration against them in London claiming uninsured losses. The insurers, RAS, initiated Italian court proceedings against West Tankers to recover amounts paid to the insured. In 2005, Colman J granted an injunction restraining RAS from pursuing the Italian proceedings on the basis that it was not inconsistent with the Brussels Regulation to do so. The House of Lords' Opinion of 21 February 2007 provides a clear summary of the English court's jurisdiction to grant anti-suit injunctions in the context of arbitration proceedings, and relevant decisions, from both the English Courts and the Court of Justice. The Lords emphasise the importance of party autonomy in arbitration and the legal certainty promoted by the English court's supervisory jurisdiction to restrain foreign proceedings, a tool which has been carefully developed and applied.

Although current English authority is that such injunctions are consistent with the Brussels Regulation, different views have been expressed by national judges and writers. The House of Lords recognised that the issue is of "very considerable and practical importance" and, accordingly, have referred it to the Court of Justice for a preliminary ruling.