A Court of Session judge has refused to refer to the EU Court of Justice the question of whether the United Kingdom can unilaterally revoke its notice of intention to the leave the European Union.

Lord Boyd of Duncansby refused a petition by a group of MPs and MSPs led by Green MSP Andy Wightman, which claimed that the question of law had arisen on the proper interpretation of the EU Treaties and that the issue was a matter of "very great constitutional importance".

The judge ruled that the question being asked was hypothetical and that the conditions for a reference had not been met. 

The petitioners argued that although the UK Government’s position was that notification would not be withdrawn and the choice for Parliament was to accept the deal or exit the EU with no deal, that was subordinate to the sovereign Parliament. Government could not restrict the choices Parliament could make, and Parliament might reject the deal on offer and vote instead for the UK to revoke the letter sent on 29 March 2017 and thereby remain a member of the EU on its current terms. But it was a necessary prerequisite that the article 50 notification could be withdrawn, and the only court or body that could give a definitive answer was the CJEU.

Refusing the petition, Lord Boyd stated: "What the petitioners are seeking is advice that, were a certain set of circumstances to come about, there is an alternative option that could be pursued given the political will to do so. In short the option of revocation of the article 50 notice is contingent on other factors rendering it a live possibility. At present it cannot be said that it is a live practical question."

The judge noted that the court was being asked by a number of MPs to settle a legal dispute in the middle of the legislative process. He continued: "In my opinion that is a clear and dangerous encroachment on the sovereignty of Parliament. It is for Parliament itself to determine what options it considers in the process of withdrawing from the European Union. It is for Parliament to determine what advice, if any, it requires in the course of the legislative process."

He added that the court was not there to be used by one side or another to advance one side of a political debate.

Lord Boyd did not accept that the answer to the question was necessary for the MPs to perform their parliamentary duties, adding that there was no rule of parliamentary procedure preventing MP’s from putting the option of revocation before the House of Commons. 

He added that the proposed question was as much about the powers of the European Council in the event of a revocation as it was about the right of the UK under article 50. "If the issue came before the CJEU it will have to consider not just the rights of a withdrawing member state under article 50 but also the rights of the European institutions and remaining member states."

He concluded: "The presumption is for the CJEU to accept references from the national court on the basis that it is primarily for the national court to determine whether it is necessary for the determination of a dispute before it. There are however a number of authorities which suggest that the CJEU will not engage in academic or hypothetical questions… Applying these principles I am satisfied that the question that is being asked is hypothetical. The facts upon which the CJEU would be asked to give an answer could not at this stage be ascertained, simply because they have not occurred."

Click here to view Lord Boyd's opinion.