On 10 December 2018, the Court of Justice of The European Union (CJEU) issued its judgment on whether the UK may unilaterally revoke its notification under Article 50 of the Treaty on European Union (TEU) for withdrawing from the EU, or if such a revocation requires a unanimous decision of the European Council (i.e., all the remaining 27 Member States). In its judgment, the CJEU agreed with a recent opinion of the Advocate General, finding that the UK may unilaterally decide to revoke the Article 50 notification and that requiring a unanimous decision would be incompatible with the principle that a Member State cannot be forced to leave the European Union against its will.
The final ruling of the CJEU is as follows:
Article 50 TEU must be interpreted as meaning that, where a Member State has notified the European Council, in accordance with that article, of its intention to withdraw from the European Union, that article allows that Member State — for as long as a withdrawal agreement concluded between that Member State and the European Union has not entered into force or, if no such agreement has been concluded, for as long as the two-year period laid down in Article 50(3) TEU, possibly extended in accordance with that paragraph, has not expired — to revoke that notification unilaterally, in an unequivocal and unconditional manner, by a notice addressed to the European Council in writing, after the Member State concerned has taken the revocation decision in accordance with its constitutional requirements. The purpose of that revocation is to confirm the EU membership of the Member State concerned under terms that are unchanged as regards its status as a Member State, and that revocation brings the withdrawal procedure to an end.