In a judgment which follows the findings in the Advocate General's recent opinion, the ECJ has confirmed that the UK can unilaterally revoke its Article 50 notice right up until 29 March 2019 unless a withdrawal treaty is agreed before that date.
The ECJ expressly rejected arguments put forward by the European Council and Commission in favour of requiring the unanimous consent of the European Council for a revocation to be permitted, drawing support from the principle derived from the founding Treaties that no State can be forced to withdraw from the European Union against its will.
The ECJ also confirmed that any notice of revocation must be delivered in a formal written notice after the State has made its decision to revoke in accordance with its own constitutional rules. For the UK, this would mean that such a decision has to be approved by Parliament. Crucially, though, the ECJ has also confirmed that revocation would enable the UK to remain in the EU on precisely the same terms as it was before the Article 50 notice was submitted – a very attractive proposition for staunch Remainers. With the Government's announcement of a postponement of tomorrow's vote, this decision is already allowing some MPs to see a way out of Brexit and a further opportunity to press for a second referendum, doing further damage to Mrs May's quest to get a vote in favour of her draft withdrawal agreement.