The European Union's top court ruled on Monday that the UK can reverse its decision to leave the EU and cancel Brexit, without consulting the other member states.
In an emergency judgment − delivered just a day before the UK parliament is due to vote on a Brexit deal agreed with the EU by Prime Minister Theresa May − the Court of Justice said: "The United Kingdom is free to revoke unilaterally the notification of its intention to withdraw from the EU."
The ruling that Article 50 can be revoked is in line with an opinion delivered last week by a Court legal adviser. This boosted the hopes of British Remain voters that a second referendum could be held, which would prevent Britain's scheduled departure from the EU on March 29, 2019.
The case was brought by a cross-party group of politicians, including Scottish Green MSPs Andy Wightman and Ross Greer, SNP MEP Alyn Smith and MP Joanna Cherry and Labour MEPs David Martin and Catherine Stihler.
May faces heavy opposition in parliament to her Brexit deal, which is widely expected to be rejected in the vote in the House of Commons on Tuesday night − which will mean tense talks with the EU when she goes to Brussels on Thursday for a summit of national leaders.