In a busy day for contenders announcing their bids, ITV News Reporter Harry Horton rounds up who's said what
Four new contenders have entered into the race to replace Boris Johnson, with former health secretaries Jeremy Hunt and Sajid Javid announcing their respective bids within hours of chancellor Nadhim Zahawi and transport secretary Grant Shapps coming forward.
Mr Zahawi, the newly elected chancellor, and Mr Shapps both announced their intentions within the space of an hour on Saturday.
It means the number in the running is now up to eight with Kemi Badenoch, Rishi Sunak, Tom Tugendhat, and Suella Braverman also in the race.
Out of the race is Defence Secretary Ben Wallace who has announced he will not be standing. Tipped to be a front-runner, should he mount a campaign, Mr Wallace said his focus is on his current role and "keeping this great country safe."
Mr Zahawi, who was brought in to replace Mr Sunak after his resignation, was one of Mr Johnson's newly appointed ministers who called for his resignation on Thursday.
The PM eventually announced he would be stepping down later that day.
In a statement, Mr Zahawi said: "The Conservative Party has made me who I am today [...] under Margaret Thatcher, the Britain I knew was full of boundless optimism and opportunity.
"That has been lost and a change is needed".
Michelle Donelan, who resigned from the role of education secretary on Thursday – less than 36 hours after accepting it, said she was backing Mr Zahawi to be the next leader.
Who else is going to run and just how many will join the race?
Mr Shapps, launching his bid in The Times, said he will end “tactical government by an often distracted centre”.
The current transport minister also urged Mr Johnson to stand aside earlier this week after a series of scandals rocked his premiership.
Announcing their respective bids in the Telegraph, both Mr Javid and Mr Hunt pledged to cancel Mr Sunak’s planned rise in corporation tax, and instead cut the 25% rate to 15%.
They give separate interviews to the newspaper, with Mr Javid also pledging to scrap the national insurance rise that was brought in when he was health secretary to help pay for the NHS and social care.
He said: “I’m not sure I would have done it if I had been chancellor, but I was focused on my job and I’m not trying to do other people’s jobs for them.”
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Tories are now rushing to take sides as more candidates announce their bids.
Having launched his campaign on Friday night, among those publicly backing Mr Sunak are Commons Leader Mark Spencer, former Tory Party co-chair Oliver Dowden, former chief whip Mark Harper, ex-ministers Liam Fox and Andrew Murrison, and MPs Sir Bob Neill and Paul Maynard.
Former minister Steve Baker, meanwhile, has backed Attorney General Suella Braverman’s campaign, who announced her intention on ITV's Peston show.
Former equalities minister Kemi Badenoch has also thrown her hat into the ring, with a plan for a smaller state and a government “focused on the essentials.”
Tom Tugendhat, the chair of the Commons Foreign Affairs Committee, has already said he will be be putting his name forward.
Foreign Secretary Liz Truss is widely expected to run with three MPs (Chloe Smith, Julian Knight and chief secretary to the treasury Simon Clarke) already expressing their support for the senior cabinet minister - though she is yet to launch a bid.
Another potential front-runner is trade minister Penny Mordaunt.
Ms Mordaunt has heavily suggested she will throw her hat in the ring, sharing an article on Saturday night from Dr Gerard Lyons, Mr Johnson’s former chief economic adviser as London mayor, which stated she would make a “great prime minister”.
She also pushed back against those who may want to depict her as “woke” in a Twitter thread early on Sunday morning, as she sought to clarify how she would define a woman.
It was reported on Saturday that Mr Johnson intends to stand down as prime minister on Monday in order to run again for Tory leader.
But this suggestion was knocked down by a spokesperson for Mr Johnson as completely untrue.
As candidates have started to make their move, Tory MP Sir Charles Walker said it is incumbent on those running for leader that they “don’t knock lumps out of each other”.
What happens next?
Following elections to the executive of the backbench 1922 Committee on Monday, the new body will draw up a timetable for the leadership election.
After his acrimonious resignation speech on Thursday, many MPs are anxious to see Mr Johnson out of No 10 as quickly as possible, fearing a summer of “chaos” if he remains.
Watch Boris Johnson's announcement on his resignation in full:
Downing Street however insisted he would not stand aside to allow Mr Raab to take over as a caretaker prime minister.
Labour has confirmed that it will table a Commons vote of no confidence in the government if Mr Johnson refuses to go voluntarily.
In order to succeed, however, it would require Tory MPs to vote with them – or at least abstain in large numbers – which would appear unlikely given it could lead to a general election they are likely to lose.