In a humiliating blow to the prime minister, the EU27 issued a statement saying the withdrawal agreement was “not open for renegotiation”, and scrapped written commitments to help her pass her deal through parliament.
Ms May went to Brussels on Thursday seeking fresh concessions amid concerns from Brexiteers over the controversial Irish backstop plan.
Her appeal came after she survived a no-confidence vote, triggered by restive Tory backbenchers angered by her decision to pull a crunch vote on her Brexit deal.
Former prime minister Mr Blair, who has backed The Independent’s Final Say campaign, said there “will be a majority in parliament in the end for a referendum”, as Ms May’s deal is looking increasingly unlikely to command support.
He said it was “completely predictable” that attempts to change her backstop plan would fail, as the Irish premier Leo Varadkar would not concede on the issue, and other EU leaders would not desert him.
“Obviously, if you come to a choice between a referendum and a no deal, it’s clear that whatever the British people voted for in June 2016, they didn’t vote for crashing out of the EU without a deal,” Mr Blair told BBC Radio 4’s Today programme.
“It’s perfectly possible for her to become the facilitator and say there are various options [Norway-style, Canada, no deal].
“If we cannot have a parliamentary majority for any of those options then it becomes logical to say to the British people – parliament is gridlocked, parliament can’t decide and therefore we have got to take it back to the British people to decide.”
Mr Blair made the comments ahead of a speech in London, where he urged European leaders to prepare for the likelihood of Brexit being delayed beyond March 2019.
The former Labour leader said: “We are now entering a new phase of Brexit.
“Government has lost the initiative. Parliament has taken it. We know the options for Brexit. Parliament will have to decide on one of them. If parliament can’t then it should decide to go back to the people.
“Now should be the time of preparation – parliament to make sure it can canvas the options in sensible manner, one by one, to reach agreement on an option or a referendum; Europe to ensure that if Britain is ready to think again, Europe is ready also to think again.
“All that is necessary is for leadership: in parliament if not in government, and in Europe where despite all the myriad of challenges European leaders have, they should understand that changing Brexit would be the greatest boost to Europe’s economy and politics and that therefore, they need to focus on the part they can play and play it.”