The European Union’s top court ruled today that the United Kingdom can unilaterally reverse Brexit anytime before March 29—the deadline for the U.K. to leave the European Union under the current schedule. The ruling comes as British Prime Minister Theresa May moments ago called off a parliamentary vote amid vocal opposition, including from within her own Conservative Party. If May fails to pass a vote on Brexit, it could undergo a second referendum. Thousands of demonstrators from both the Remain and pro-Brexit camps took to the streets in London over the weekend ahead of the crucial vote.