The UK is free to revoke unilaterally the notification under TEU, art 50 of its intention to withdraw from the EU. Such a revocation, decided in accordance with its own national constitutional requirements, would have the effect that the UK remains in the EU under terms that are unchanged as regards its status as a Member State.
Aidan O’Neill QC was involved in this case.
CJEU Press Releasehttps://curia.europa.eu/jcms/jcms/p1_1512505/en/
Curia Website (Judgment & AG’s Opinion)http://curia.europa.eu/juris/documents.jsf?num=C-621/18