On Tuesday, Britain's House of Commons is scheduled to vote on, and expected to reject, Prime Minister Theresa May's negotiated Brexit plan, throwing Britain's exit from the European Union into further uncharted waters. On Monday morning, the European Court of Justice, the EU's top court, answered one unresolved Brexit question, ruling that if Britain so desires, it can unilaterally cancel its divorce any time before it becomes final on March 29, 2019 — or during any extension to that exit date. Revoking the Article 50 exit clause would have to "follow a democratic process," the court ruled, meaning that in Britain, Parliament would have to approve calling off Brexit.
The ECJ issued its ruling in response to a question from a group of anti-Brexit U.K. politicians, and the court said Monday that its aim is to "clarify the options open to MPs" before they vote on Tuesday. The upshot is that staying in the EU is now "a real, viable option," BBC Brussels correspondent Adam Fleming notes, cautioning that "a lot would have to change in British politics" for Brexit to be actually called off.
Assuming lawmakers rejected May's proposal, Parliament could "follow a number of different courses of action, including backing a Norway-type deal or amendments that make significant changes made to the backstop agreement — the insurance policy that prevents a hard border in Ireland," Laura Silver says at BuzzFeed News. "The defeat would also pave the way to a second referendum on leaving the EU, which has already been discussed in Downing Street. It is unclear whether or not remaining in the EU entirely would be an option on the ballot paper."