LUXEMBOURG/BRUSSELS (Reuters) - The European Union’s top court ruled on Monday that the British government may reverse its decision to leave the bloc without consulting other member states, a decision welcomed by those campaigning to stop Brexit.

In an emergency judgment delivered just 36 hours before it expected the British parliament to vote on a Brexit deal agreed with the EU by Prime Minister Theresa May, the Court of Justice (ECJ) said: “The United Kingdom is free to revoke unilaterally the notification of its intention to withdraw from the EU.”

May later postponed that vote in the face of defeat, throwing the Brexit process into disarray.

The heightened uncertainty over how and even whether Britain can arrange to leave lent even greater significance to the ruling, which also indicated that Britain may, if others agree, postpone its withdrawal from March 29 in order to hold a rerun of its 2016 vote on EU membership. May rejects holding a new Brexit referendum but her hold on office is looking shaky.

The ruling, clarifying Article 50 of the EU treaty, rejected arguments put forward by the EU executive, which said other EU states would need to agree, partly on the grounds that otherwise governments could use threats of withdrawal to gain advantage.

Britain’s foreign minister Jeremy Hunt said the ruling was “irrelevant” as the government would not change course, and warned that the 52 percent of Britons who voted to leave the EU would be “shocked and very angry” if it did.

A minister in the devolved Scottish government, which backed the referral of the case to the ECJ, noted that most Scots had voted against Brexit. Michael Russell said the judgment “exposes as false the idea that the only choice is between bad deal negotiated by the UK government or the disaster of no deal”.

FILE PHOTO: Anti-Brexit demonstrators wave flags during a protest opposite the Houses of Parliament, London, Britain, December 4, 2018. REUTERS/Henry Nicholls/File Photo

THREE OPTIONS, NOT TWO

The Court itself said it had ruled with unprecedented haste to show British lawmakers they have three options not two -- leave on agreed terms, leave without a deal or not leave at all.

The ECJ argued that a national right to leave should be matched by an equally sovereign right to reverse that.

It cited the EU treaty goal of “ever closer union among the peoples of Europe” - a clause hated by Brexit campaigners - to argue that states cannot be forced out against their will.

Some Brexit champions accuse the ECJ of political meddling. “No surprise,” tweeted Nigel Farage, former leader of the UK Independence Party. “The collusion to stop Brexit continues.”

The judges insist they only interpret EU legislation. But some observers say significant recent decisions indicate that the ECJ is keen to defuse nationalist pressures threatening to break up the EU by favouring arguments for national sovereignty.

“The court does aim to keep the Union together,” said Suzanne Schmidt, a professor at Bremen University who has researched the ECJ’s role in EU policy.

“A court having a strong EU as its vision is highly likely to try to keep the door open for member states.”

The court also challenged a view in Brussels that if Britain stayed it might lose some privileges it has built up over the years, including a hefty rebate on its EU budget contributions.

It is far from clear whether or how Britain could organise a new referendum. Opinion polls suggest that any new majority for staying in the EU is narrow and many in the EU question the wisdom of keeping such a divided country as a member.