Theresa May will face a vote of no confidence tonight as enough Tory MPs have sent letters triggering the vote.
The announcement was made by chairman of the backbench 1922 Committee Sir Graham Brady.
In a letter Sir Graham said: “The threshold of 15% of the parliamentary party seeking a vote of no confidence in the leader of the Conservative Party has been exceeded.”
The vote will be held on Wednesday evening between 6pm and 8pm.
The votes are counted immediately and an announcement “will be made as soon as possible.”
At least 48 MPs have sent letters to Sir Graham to trigger the vote of no confidence.
Under party rules, a contest is held if 15 percent of Conservative MPs write to the chair of the committee of Tory backbenchers.
Foreign Secretary Jeremy Hunt has given his full support to Mrs May and said he will backing her in the vote tonight.
In a tweet Mr Hunt said: “I am backing @theresa_may tonight. Being PM most difficult job imaginable right now and the last thing the country needs is a damaging and long leadership contest. Brett was never going to be easy but she is the best person to make sure we actually leave the EU on March 29.”
The prime minister needs the backing of at least 158 Tory MPs to see off the challenge by the Brexiteers.
Although she could choose to resign if votes against her were below the number to topple her but significant enough in number.
The vote of no confidence comes after she abruptly announced the delay of the meaningful vote which was meant to be held on Tuesday, as she knew she would face defeat.
Mrs May’s withdrawal agreement has faced staunch opposition from MPs who have issues over the backstop.
The prime minister then promptly travelled to Europe to get assurances and clarifications from EU leaders about the deal.
In a joint statement, the chairman of the pro-Brexit Conservative European Research Group Jacob Rees-Mogg and his deputy Steve Baker said: “Theresa May’s plan would bring down the Government if carried forward. But our party will rightly not tolerate it.
“Conservatives must now answer whether they wish to draw ever closer to an election under Mrs May’s leadership. In the national interest, she must go.”
Theresa May no confidence vote odds
Theresa May has odds of 1/2 to win the vote of no confidence tonight and survive the challenge against her, according to Betfair, whereas Ladbrokes has made it evens Mrs May loses and 8/11 she wins.
Theresa May replacement odds
According to Coral, these are the latest odds over who will replace Theresa May if she is ousted as leader of the Conservative Party.
Boris Johnson – 5/1
Dominic Raab – 5/1
Sajid Javid – 8/1
Michael Gove – 7/1