LONDON — British lawmakers on Thursday voted to postpone the country’s departure from the European Union but, in a rare victory for Prime Minister Theresa May, narrowly failed to wrest control of the Brexit process from her battered government.
After days of turmoil, Mrs. May fended off — by just two votes — a remarkable power grab by lawmakers frustrated at months of political deadlock that has left the country in limbo with just 15 days to go before its scheduled departure from the bloc.
They later voted by 412 to 202 for a motion that means that Britain will almost certainly not leave the European Union as scheduled on March 29, as Mrs. May has repeatedly promised it would.
What remains unclear now is how long the delay will be. Mrs. May plans to hold a third vote on her unpopular plan for withdrawal, despite have suffered two staggering defeats on it already.
If the prime minister should succeed in a third attempt, she would then request a short delay — no more than three months — from European Union leaders. That presumably would be agreed to next week at a European Union summit in Brussels.
But the motion noted that should her plan go down to defeat once again, Mrs. May might have to ask European leaders for a much longer delay, with unknown consequences.
The votes on Thursday were a relief for Mrs. May, whose control over the withdrawal process, or Brexit, has melted away in recent days, culminating in open defiance from members of her own cabinet in a vote on Wednesday rejecting a “no-deal” Brexit.
It had long seemed possible that a cross-party consensus for a softer Brexit existed within the House of Commons, but that proved not to be the case.
Some analysts said that was no great surprise.
“Ultimately, these are people who have spent their careers competing against the people they now have to work with to get things passed,” said Rob Ford, a professor of politics at the University of Manchester. “They’re Labour and Tory first, and ‘Leave’ and ‘Remain’ second.
“These are people who have spent their whole lives working for one tribe,” Mr. Ford added, “and the other tribe is the baddies. The other tribe is the people they went into politics to overcome. There’s a lot there to overcome, psychologically and historically.”
And so lawmakers could not quite bring themselves to allow the body to test whether a majority would support a softer Brexit than Mrs. May has offered. That would mean leaving the European Union but remaining in a customs union with the bloc, or keeping even closer ties, minimizing the economic dislocation.
Instead, Parliament has effectively given Mrs. May another chance to press ahead with her withdrawal agreement, most likely next Tuesday.
Mrs. May and her allies are again working to win over 10 lawmakers from Northern Ireland’s Democratic Unionist Party, and a bigger group of pro-Brexit hard-liners in her own Conservative Party.
The amendments came at the end of a week that has been dismal for Mrs. May.
On Tuesday, Parliament rejected her plan for a second time, by a vote of 391 to 242. Then, on Wednesday, Parliament voted 312 to 308 for an amendment ruling out a disorderly no-deal Brexit, badly undercutting Mrs. May’s authority and negotiating leverage.
Four amendments were tabled on Thursday, each wresting a degree of control away from Mrs. May.
The amendment to take control of the process failed by 314 votes to 312. Oliver Letwin, a Conservative Party lawmaker who co-sponsored the measure, calling for nonbinding votes, told the government he and his colleagues had entered into rebellion reluctantly.
“None of us who has put this forward prefer to grab the order paper,” he said, addressing one of Mrs. May’s top lieutenants in debate at the House of Commons. “None of us prefer these elaborate devices. We seek above all, and only, to ensure that the House has the opportunity to rescue our fellow citizens from a fate that both he and I wish to avoid.”
Sarah Wollaston, an independent lawmaker, whose amendment supporting a second referendum failed by 334 to 85, used her medical background to argue that, “if we talk about this in strictly clinical terms,” the popular consent for Brexit had expired.
“Nobody would seriously proceed on the basis of a consent form that was signed nearly three years ago,” she said. “And furthermore, for young people in this country, they face being wheeled into the operating theater for major constitutional, social and economic surgery based on a consent form that was signed by their grandparents three years ago.”
Delaying Brexit can happen only with the consent of the European Union, and up until now the bloc’s position has seemed clear: Only a general election or a second Brexit referendum would justify letting Britain postpone its departure by more than a few months.
But on Thursday, there were signs of flexibility when Donald Tusk, the president of the European Council, said European leaders should be “open to a long extension” of Britain’s membership.
The comments will give weight to Mrs. May’s threat to pro-Brexit politicians that unless they back her deal in a third vote next week, they will face a long delay. That could increase the prospects of a second referendum — and that could mean that Brexit might never happen.
Already some pro-Brexit rebels have folded, including David Davis, who resigned as Brexit secretary in protest over Mrs. May’s deal, but who voted to support it on Tuesday.
Though some of the hard-liners are likely to cave in, it is unlikely that all of them will. Some believe Mrs. May’s days are numbered and are sure that her successor will be a Brexit enthusiast, perhaps Boris Johnson, the former foreign secretary.
Were he or someone like him in charge, they would have little to fear from a long extension of the Brexit process, some argue.
One pro-Brexit legal expert, Martin Howe, argued recently in an article on the Conservative Home website, that Britain would be “much better off than under the deal” negotiated by Mrs. May. At the end of the extension, he said, Britain would be “free to leave on 1 January 2021 without being trapped in the ‘backstop’ protocol” involving the Irish border.
The question then would be how many Brexit supporters would hold out against Mrs. May’s deal, and whether she could attract enough sympathizers from the opposition Labour Party to squeak her plan through.
At the end of the voting on Thursday, the Labour leader, Jeremy Corbyn, who had ordered his lawmakers to abstain on the Wollaston amendment, stood up and called for a second vote on Brexit. That earned him a cacophony of catcalls for his head spinning volte-face.