Penny Mordaunt has become the first MP to enter the race to replace Liz Truss as prime minister after her dramatic resignation yesterday.
The leader of the Commons announced her candidacy in a tweet on Friday afternoon, saying fellow Conservatives had urged her to stand.
Ms Mordaunt, who came third in the last leadership race behind Ms Truss and Rishi Sunak, wrote: “I’ve been encouraged by support from colleagues who want a fresh start, a united party and leadership in the national interest.
“I’m running to be the leader of the Conservative Party and your prime minister – to unite our country, deliver our pledges and win the next general election.”
Ms Mordaunt needs to secure the backing of at least 100 Tory MPs by Monday afternoon to stay in the race.
So far, 18 MPs have publicly stated they will vote for her.
Mr Sunak, the former chancellor, is also expected to launch his own bid, with 76 MPs publicly supporting him.
The list includes ex-Chief Secretary to the Treasury Chris Philp and another former Chancellor Sajid Javid, who said Mr Sunak had “the leadership our country needs, and the values our party needs”.
Speculation is also mounting that Boris Johnson, who is thought to be on holiday in the Caribbean, could take another shot at the top job too.
The former prime minister’s close ally, Tory MP Sir James Duddridge, told Sky News he had spoken to him on the phone, and he said he was “up for it”, adding: “I’m going to do it, Dudders!”.
Mr Johnson has 44 public backers so far, including five cabinet ministers – Jacob Rees-Mogg, Ben Wallace, Simon Clarke, Alok Sharma and Anne-Marie Trevelyan.
Nominations opened on Thursday and will close at 2pm on Monday. Candidates must have 100 nominations to go through to the next round and as there are 357 Tory MPs in the Commons, there will be a maximum of three candidates.
MPs will narrow the field to two before a final indicative vote, after which the party members will vote online – unless the Tories coalesce around one candidate or the trailing contender bows out.
If the members vote, the winner will be announced on Friday.
Ms Mordaunt’s announcement came after she reportedly held talks with Jeremy Hunt, the chancellor, in which she is said to have assured him he could stay on in his role if she wins the contest.
Sources close to the candidate also said she had made clear his medium-term fiscal plan, set to be announced on 31 October, would go ahead under her premiership.
Downing Street confirmed it would be up to the next PM to decided whether to continue with Mr Hunt’s plans.
But former Bank of England deputy governor Sir Charlie Bean warned they would have no choice but to stick to it.
He told the BBC: “It would be even worse if the new prime minister decided they wanted to replace Jeremy Hunt with another chancellor. That really would create a lot of volatility in the financial markets.”
In the last leadership election, Ms Mordaunt won 105 nominations, behind Mr Sunak’s 137 and Ms Truss’s 113.
Ms Truss won the final round of voting among Tory party members after campaigning on a mandate to cut taxes to boost economic growth.
This ultimately proved to be her downfall after her mini-budget unleashed turmoil in the financial markets, forcing her to sack Kwasi Kwarteng as chancellor and make a series of U-turns on the economic policies that brought her into office.
Ms Truss resigned 44 days into her premiership on Thursday, making her the shortest-serving prime minister in modern British history.