He could potentially face former Chancellor of the Exchequer, Rishi Sunak, and ex-trade minister Penny Mordaunt in a vote by MPs on Monday.
He is thought to be on holiday in the Caribbean and has not made any comment on his future, but a number of Conservative MPs have come out in support of his candidature.
On Thursday Jane Hunt, MP for Loughborough, wrote on Twitter: “Just to make my feelings known publicly, they haven’t changed. I’m backing Boris!”
She was joined on Friday by Business Secretary Jacob Rees-Mogg, who wrote on Twitter, “I’m backing Boris.”
Defence Secretary Ben Wallace, who had been considered a dark horse for the Conservative Party leadership contest, has ruled himself out and called for the winner to make investment in the armed forces and intelligence agencies.
In a veiled reference to Russia, Wallace wrote on Twitter, “I am privileged to be the UK Defence Secretary and the current threat requires stability in that office.”
“I will be looking to all candidates to recognise that you cannot have economic security at home without national security,” Wallace added.
Truss pipped Mordaunt to make the final two in the summer’s leadership contest and then defeated Sunak, and it now looks as if it might be a three-horse race between Sunak, Mordaunt, and Johnson.
Mordaunt was appointed as leader of the Commons by Truss but was overlooked for one of the key Cabinet ministerial jobs.
Mordaunt is reportedly “taking soundings” from MPs about the prospects of her winning the contest.
Her lack of experience could count against her in a contest with Johnson and Sunak, especially considering the poor performance of Truss, who had held several important ministerial roles including foreign secretary but showed little knowledge of how her policies would be greeted by the financial markets.
Sunak Is ‘Man With the Experience and Skill’: MP
Gary Streeter, MP for South West Devon, gave his support to Sunak and wrote on Twitter: “Now we have a chance to put the UK back on track. I will be supporting the man with the experience and skill to sort out public finances and lead an effective and competent government. “Sunak also has the backing of ministers Robert Jenrick and Claire Coutinho, and backbenchers Guy Opperman, Siobhan Baillie, Angela Richardson, and Robin Walker.
Under the rules set out by Sir Graham Brady, chairman of the backbench 1922 Committee, and Conservative Party Chairman Jake Berry, nominations will close at 2 p.m. on Monday and candidates have to have the support of at least 100 of the party’s 357 MPs in order to make it onto the ballot.
Conceivably Sunak, Mordaunt and Johnson — or a third candidate, like Suella Braverman or Kemi Badenoch — could all get 100 votes, which would mean there would have to be a ballot of MPs on Monday afternoon, with the final two making it onto the ballot.
Members of the party will be asked to vote online, with the winner and new Prime Minister being announced on Friday, October 28.
The leader of the opposition Labour Party, Sir Keir Starmer, called for an immediate general election and said the return of Johnson, who he said was considered “unfit for office” by his own MPs in July just added “insult to injury” for voters.
But with the Tories trailing Labour in the opinion polls, the new leader and Prime Minister is unlikely to want to call an election for at least 12 months and does not have to call one until January 2025 at the latest.