Theresa May has told Conservative MPs she will not lead the party into the next general election.

The promise came as the Prime Minister fought to retain her place as Tory leader ahead of a confidence vote of MPs.

Mrs May addressed Conservative MPs at a meeting of the backbench 1922 Committee moments before the crucial vote began at 6pm.

BrexitConservative MPs in a meeting addressed by Theresa May in Committee Room 14 of the Houses of Parliament (Stefan Rousseau/PA)

Afterwards, Cabinet minister Amber Rudd said: “She’s made the commitment that I think is what people wanted, but she was very clear that she won’t be taking the general election in 2022.”

Solicitor General Robert Buckland told reporters: “She said ‘In my heart I would like to lead the party into the next election’ and then that was the introductory phrase to her indication that she would accept the fact that that would not happen, that is not her intention.”

Brexiteer Jacob Rees-Mogg said he was not persuaded to vote for the Prime Minister in the ballot.

He told the Press Association: “It was all the same old stuff. Nothing has changed.”

Conservative MP Nick Boles tweeted: “Theresa May was crystal clear: she will not lead the Conservative Party into the next general election. She now deserves the support of all Conservative MPs so she can get on with the job of delivering a Brexit compromise that can win a Commons majority.”

Mrs May looked set to see off the challenge to her leadership, as scores of Tory MPs made public statements of support ahead of the confidence vote.

Mrs May responded with defiance to the news that the threshold of 48 letters from Tory MPs demanding a confidence vote had been passed, declaring that she would fight for her job “with everything I’ve got”.

Every MP in her Cabinet swiftly issued statements of support and she was greeted by loud cheers from the Tory backbenches when she faced the House of Commons for her weekly session of Prime Minister’s Questions.

By early afternoon, the number of Conservative MPs saying publicly that they would vote for her had passed the 159 required for her to survive the attempt to oust her.

The target for victory, representing half of the parliamentary party plus one, increased from 158 during the day, as the Conservative whip was restored to Burton MP Andrew Griffiths and Dover MP Charlie Elphicke.

Mr Griffiths, a former chief of staff to Mrs May who had been suspended over suggestive text messages, immediately confirmed he would back the PM.

However, uncertainty remained over whether public statements would translate into votes in the secret ballot taking place in a Commons committee room between 6pm and 8pm.

Downing Street aides declined to discuss whether the PM would stay on if she won by only a slender margin.

Prime Minister’s QuestionsTheresa May speaks during Prime Minister’s Questions hours after being told she faces a confidence vote (Mark Duffy/House of Commons/PA)

Failure in the ballot would trigger a leadership contest in which Mrs May could not stand.

But if she wins, another challenge cannot be mounted against her position as Tory leader for a year.

Mrs May was informed that she would face a ballot by the chairman of the 1922 Committee, Sir Graham Brady, in a phone call at 10.35pm on Tuesday.

She had just returned to 10 Downing Street from a day of travels which had taken her to The Hague, Berlin and Brussels for Brexit talks with EU leaders.

(PA Graphics)

As day broke in Westminster on Wednesday, Sir Graham issued a press release announcing that the threshold had been reached and a confidence vote would be held later that day.

In a dramatic early morning statement outside the door to 10 Downing Street, Mrs May responded: “I will contest that vote with everything I’ve got.”

Warning that a change of prime minister would put the UK’s future at risk and could delay or halt Brexit, she insisted she would stay on to “finish the job”.

Mrs May said securing a Brexit deal which will deliver on the result of the 2016 referendum was “now within our grasp” and said she was “making progress” in securing reassurances from EU leaders on MPs’ concerns about the proposed backstop for the Irish border.

Prime ministers with shortest time in office since 1900(PA Graphics)

Husband Philip showed his support by watching Prime Minister’s Questions from the public gallery, while Tory elder statesman Kenneth Clarke told MPs that a leadership contest would be “irresponsible and unhelpful”.

None of the PM’s Brexit-backing critics took the opportunity to attack her, while there were strong words of support from backbenchers including Neil O’Brien (Harborough), who condemned “headbangers from all sides” for undermining her.

But she faced a call to stand down from the Scottish National Party’s leader in Westminster, Ian Blackford, who said: “This Government is a farce, the Tory Party is in chaos and the Prime Minister is a disgrace… Prime Minister, take responsibility, do the right thing, resign.”

Mrs May cleared the decks to lobby Tory MPs for their backing, cancelling a planned meeting of Cabinet and a trip to Dublin for talks with Irish premier Leo Varadkar.