The Supreme Court this morning (24 January 2017) handed down its decision in the government’s appeal against the successful legal challenge to the use of the Royal Prerogative to give effect to Brexit, brought by Gina Miller and others. The case, in which four separate groups of claimants argued that only Parliament can invoke Article 50 of the Lisbon Treaty and sought a declaration that any attempt to invoke Article 50 through other means would be ultra vires, was heard in the High Court in October 2016, followed swiftly by the “leapfrog” appeal to the Supreme Court in December 2016. A separate appeal, as to whether the UK government is obliged to consult the devolved governments of Scotland, Wales and Northern Ireland, was also heard by the Supreme Court at the same time.

Lord Neuberger, the President of the Supreme Court, read out a short summary of the court’s decision at 9.30am. By a majority of 8-3 (Lord Neuberger, Lady Hale, Lord Mance, Lord Kerr, Lord Clarke, Lord Wilson, Lord Sumption and Lord Hodge in the majority with Lord Reed, Lord Carnwath and Lord Hughes dissenting), the Supreme Court dismissed the government’s appeal, finding that “Withdrawal makes a fundamental change to the UK’s constitutional arrangements, by cutting off the source of EU law. Such a fundamental change will be the inevitable effect of a Notice being served. The UK constitution requires such changes to be effected by Parliamentary legislation.” (quote taken from Lord Neuberger’s summary).

On the devolution question, the Supreme Court was unanimous in its decision that relations with the EU are a matter for the UK government alone, and that UK ministers are therefore not legally required to consult with the devolved governments prior to triggering Article 50.

Widely anticipated though this decision has been, it does not bring to an end all legal challenges to the process of the UK’s separation from the EU. At least two other challenges have been issued in recent weeks, both seeking clarification in the English and Welsh High Court as to whether a departure from the EU also means a withdrawal from the European Economic Area. The claims, brought by a group called British Influence and four anonymous individuals, are likely to be consolidated. Crowdfunded proceedings are also expected in Ireland this spring to determine whether the triggering of Article 50 is reversible as a matter of EU law.

We will continue to monitor and report on developments over the coming months.