Britain's Prime Minister Theresa May leaves after giving a news briefing in Brussels, Belgium March 22, 2019. REUTERS/Toby Melville

BRUSSELS (Reuters) - After British Prime Minister Theresa May reassured them she could win a crunch vote in parliament next week to ensure an orderly Brexit, EU leaders were left even more doubtful of her chances.

Following more than an hour of explanations that with days left until Britain might crash out she could win over lawmakers who have twice rejected her EU withdrawal deal, May left the summit room on Thursday and the other 27 leaders conferred -- finding a consensus that they were even less convinced than before, officials familiar with their discussions told Reuters.

French President Emmanuel Macron told the room that before coming to Brussels he had thought May had only a 10 percent chance of winning the vote. After listening to the prime minister, he said, he had cut his estimate -- to five percent.

To general assent, one person present said, summit chair Donald Tusk shot back that Macron was being “very optimistic”.

After hours of discussion, the leaders agreed to delay Brexit beyond the deadline of next Friday -- but possibly only to April 12 or into May, trying to shift responsibility for any chaotic no-deal outcome back to London from Brussels.