Prime Minister Theresa May has won a vote of confidence in her leadership of the Conservative Party by 200 to 117.
Mrs May is now immune from a leadership challenge for a year.
Speaking in Downing Street, she vowed to deliver the Brexit “that people voted for”.
Burt she said she had listened to the concerns of MPs who voted against her and would be fighting for changes to her Brexit deal at an EU summit on Thursday.
Mrs May said she had a “renewed mission – delivering the Brexit people voted for, bringing the country back together and building a country that really works for everyone.”
The prime minister won the confidence vote with a majority of 83, with 63% of Conservative MPs backing her and 37% voting against her.
The BBC’s Laura Kuenssberg said the result was “not at all comfortable” for the prime minister and a “real blow” to her authority.
The confidence vote was triggered by 48 of her MPs angry at her Brexit policy, which they say betrays the 2016 referendum result.
Jacob Rees-Mogg, who led calls for the confidence vote, said it was a “terrible result for the prime minister” and called on her to resign.
Cabinet minister Chris Grayling said: “This has hardly been a joyful day for the Conservative Party but it has voted very comfortably that it wants her to stay, wants her to take us through Brexit.”
The result was greeted by cheers and applause from Tory MPs as it was announced by backbench Tory chairman Sir Graham Brady.
The prime minister still faces a battle to get the Brexit deal she agreed with the EU through the UK Parliament, with all opposition parties and, clearly, dozens of her own MPs against it.
Labour frontbencher Rebecca Long-Bailey said: “This deal that she has on the table will not get through Parliament.”
She said Labour would table a no-confidence motion that all MPs – not just Conservatives – will be able to vote in when they felt they had a chance of winning it, and forcing a general election.
DUP deputy leader Nigel Dodds said his party, which helps keep Mrs May in power, was still concerned about the Irish backstop plan, which most MPs were against.
“I don’t think this vote really changes anything very much in terms of the arithmetic,” he told BBC News.
But he said the DUP would not support a no-confidence motion in Parliament at this stage.
The SNP’s Stephen Gethins urged Labour to “step up to the plate” and call a vote of no confidence in Mrs May, accusing the government of “playing games with people’s lives”.
Mrs May earlier vowed to fight on to deliver her Brexit deal, which she argues is the only option for leaving the EU in an orderly way on 29 March.
But in a last-minute pitch to her MPs before the vote she promised to stand down as leader before the next scheduled election in 2022.
If she had lost the confidence vote Mrs May would have been forced to stand down as Conservative Party leader, and then as prime minister.
But she is now expected to travel to a summit in Brussels on Thursday to continue trying to persuade EU leaders to change the deal – they have previously said it can not be renegotiated.