European judges will consider whether the UK can choose to revoke its notice to leave the European Union, after the UK Supreme Court refused permission to the Government to appeal against the Court of Session ruling referring the question.

Lady Hale, the President, Deputy President Lord Reed and Lord Hodge, the another Scottish Justice apart from Lord Reed, today ruled that the Court of Session order requesting a ruling from the EU Court of Justice was not capable of being appealed.

The decision was given in the petition for judicial review brought by a cross-party group of MPs, MEPs and MSPs led by Green MSP Andy Wightman, who are seeking a definitive ruling from the EU court on whether the UK can change its mind about leaving the EU, without having to secure the consent of the other member states. They claim an answer to the question is necessary so that those who have to vote on any agreement reached are fully informed of the options open.

The UK Government has argued that the question is hypothetical, since it has no intention of revoking the notice, and therefore not a matter that should be considered by the courts.

After the First Division, under Lord President Carloway, agreed that it was proper to request a ruling (click here for news report), it refused permission to appeal that decision and the Government applied direct to the Supreme Court. 

In a written note the Justices point out that under s 40 of the Court of Session Act 1988, the only basis on which an appeal against the interlocutors (formal court orders) in question might be taken would be if they constituted "a decision constituting final judgment in any proceedings". "Final judgment" is defined as meaning "a decision which, by itself or taken along with prior decisions in the proceedings, disposes of the subject matter of the proceedings on its merits". If they did not, it followed that the Supreme Court had no jurisdiction to hear an appeal.

It was clear, they state, that the interlocutor requesting a ruling did not constitute a final judgment. Contrary to the Secretary of State’s contention, it was not "interlocutory in form but final in substance". The request to the CJEU did not in itself "dispose of the subject matter" of the proceedings: it remained to be seen what remedy, if any, the Court of Session would grant. That would remain the position even after the CJEU made a ruling on the question referred. The purpose of the ruling was, as stated in the relevant EU Treaty, "to enable [the national court] to give judgment", and a preliminary ruling was merely a step in the proceedings pending before the national court, which had to assume responsibility for the subsequent judicial decision.

It therefore remained for the Court of Session to give judgment in the light of the preliminary ruling, any relevant facts which it might find and any relevant rules of domestic law, and it was only then that there would be a final judgment in the proceedings.

The case will be heard at the CJEU on 27 November.

Click here to view the full reasons.