A top legal adviser to the Court of Justice of the European Union has recommended that the UK be allowed to cancel its Article 50 notification triggering Brexit and stay in the EU if it wants. Advocate General Sánchez-Bordona writes in an Opinion released this morning that the UK has the legal right to withdraw its Article 50 notification, even without the agreement of other EU countries — so long as this happens before the withdrawal agreement is concluded and has parliamentary approval.

The Opinion has not yet been published now been published in full and is summarised in a press release, reproduced in full below.

An Advocate General’s Opinion is non-binding but highly influential: the Court of Justice does not have to follow it, but mostly does. Its ruling is expected later this month.

The Advocate General states that “unilateral revocation” of Article 50 would be “a manifestation of the sovereignty of the departing Member State”. He also found that it would make no sense to force out a member state that has changed its mind about leaving, as it would only turn around and apply again to join.

It also makes sense, according to the Advocate General, to allow unilateral revocation in light of the EU’s general tendency towards keeping countries in rather than kicking them out:

Not placing obstacles in the way of the continued EU membership of a Member State that decides to leave the European Union, but then changes its stance, in accordance with its constitutional requirements, and wishes to continue being a member, therefore appears, in my view, to be an especially appropriate interpretative approach.

But there are conditions. Unilateral revocation must:

1. be notified formally to the European Council.
2. have parliamentary approval in the same way as the withdrawal notification (i.e. legislation must be passed)
3. happen in the two-year negotiation period that ends, for the UK, on 29 March 2019
4. be in good faith, in order to prevent abuse (i.e. the UK could not keep stopping and re-starting the clock to gain negotiating leverage)

If EU27 are not convinced that UK is acting in good faith, and this view is upheld by the ECJ, then the UK does not have the right to unilaterally revoke.

5.

— David Allen Green (@davidallengreen) December 4, 2018

The case was taken by a group of Scottish politicians with the support of crowdfunding. There is not yet an official date for the court’s judgment, but some time in the week beginning 17 December is a good bet according to the well-connected David Anderson QC.

Unilateral revocation of Article 50, even if legally possible, is unlikely to happen without significant political shifts. Neither the Conservative nor Labour parties are currently in favour of a second referendum, let alone Parliament cancelling Brexit without a second vote.