May is set to face a vote of no-confidence in her leadership after the required 48 MPs from her Conservative Party filed letters with the influential 1922 Committee, which represents rank-and-file Conservative MPs in the House of Commons.
U.K. Prime Minister Theresa May defended her leadership outside 10 Downing Street just before 9 a.m. Wednesday, revealing that her Conservative Party had demanded a vote of confidence in her premiership amid the tumult of Britain exiting the EU.
Sterling jumped as high as $1.2672 as the result came in but then fell to $1.2605, still up 1 per cent on the day, after it emerged that the number of lawmakers who had voted against May was higher than many in the markets had expected. If she does survive the vote, May will be immune from any new leadership challenge for one year.
Her trade minister, Liam Fox, said the government might not even put it to a vote unless the European Union gave more reassurances on the so-called Irish "backstop", an insurance policy aimed at preventing border controls on the island of Ireland.
Instead, May went to the House of Commons on Monday and conceded that the divorce deal she struck last month with European Union leaders was likely to be rejected "by a significant margin" and postponed the vote.
Votes will be counted immediately after the ballot, which is taking place between 6:00pm and 8:00pm (local time).
Backbencher Anna Soubry said it was time for the prime minister to face down hardline Brexiters on the right of her party. But at a closed meeting with Conservative lawmakers before they were due to decide her fate, she announced she would not take the party into the next election due in 2022, two lawmakers present told reporters.
"Tonight's vote makes no difference to the lives of our people", Corbyn said in a statement.
Many lawmakers have been growing angry with May over her handling of Brexit.
Parliament has until January 21 to vote on the deal, a little more than two months before Britain's March 29 departure date. She will remain leader, and prime minister, until the successor is picked. It stipulates that if no other solution can be found, the United Kingdom will remain in a customs union with the EU after Brexit to avoid a hard border. If the contest got to that stage, it would be the first time in modern British history that a ruling party held a contested leadership election.
Rees-Mogg, the head of an influential eurosceptic group of lawmakers, announced he had submitted a letter of no confidence in the Prime Minister the day after she unveiled her draft Brexit deal.
Nonetheless, the 62-year-old has proved to be a stubborn political survivor, hanging on to power amid fierce internal and external opposition, and despite a disastrous general election in June 2017.
The party membership would vote via a postal ballot on which of the two candidates should be party leader.
However, Donald Tusk, president of the European Council, has already indicated the withdrawal agreement is not up for renegotiation for European Union leaders.
"She's not the person to see Brexit through", he said.
Chancellor Philip Hammond said, "I'm very clear that the prime minister will have the support of the great majority of parliamentary colleagues".
The British pound, which has lost 25 cents against the US dollar since the 2016 referendum, was down 0.5 percent at $1.2501, falling after a Sky news reporter said a vote of confidence in May's leadership was about to be triggered.
He spoke by phone to Tusk Monday, when both reiterated the deal "is the best option and could not be renegotiated", according to his office.
Two former Brexit secretaries, David Davis and Dominic Raab, presented what they called "a better deal", at a press conference in Westminster on Wednesday.