The Full Court of the CJEU has ruled that the UK is free to revoke unilaterally the notification of its intention under Article 50 TEU to withdraw from the EU – Case C-621/18 Wightman. The judgment is in response to a request from the Inner House of the Court of Session for an advisory opinion.The Court’s (non-binding) Press Release states that:
“In today’s judgment, the Full Court has ruled that, when a Member State has notified the European Council of its intention to withdraw from the European Union, as the UK has done, that Member State is free to revoke unilaterally that notification.
That possibility exists for as long as a withdrawal agreement concluded between the EU and that Member State has not entered into force or, if no such agreement has been concluded, for as long as the two-year period from the date of the notification of the intention to withdraw from the EU, and any possible extension, has not expired.
The revocation must be decided following a democratic process in accordance with national constitutional requirements. This unequivocal and unconditional decision must be communicated in writing to the European Council.
Such a revocation confirms the EU membership of the Member State concerned under terms that are unchanged as regards its status as a Member State and brings the withdrawal procedure to an end.” [bold in original]
“In the absence of an express provision governing revocation of the notification of the intention to withdraw, that revocation is subject to the rules laid down in Article 50(1) TEU for the withdrawal itself, with the result that it may be decided unilaterally, in accordance with the constitutional requirements of the Member State concerned.
The revocation by a Member State of the notification of its intention to withdraw reflects a sovereign decision to retain its status as a Member State of the European Union, a status which is neither suspended nor altered by that notification.
The Court considers that it would be inconsistent with the EU Treaties’ purpose of creating an ever closer union among the peoples of Europe to force the withdrawal of a Member State which, having notified its intention to withdraw from the EU in accordance with its constitutional rules and following a democratic process, decides to revoke the notification of that intention through a democratic process.
To subject that right to revoke to the unanimous approval of the European Council as the Commission and Council proposed, would transform a unilateral sovereign right into a conditional right and would be incompatible with the principle that a Member State cannot be forced to leave the European Union against its will.” [bold in original]
The Full Court has therefore ruled  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.” [bold in original]