How is the Tory leadership race shaping up? ITV News Political Correspondent Carl Dinnen takes a look
Boris Johnson has refused to give his support to any of the 11 candidates hoping to replace him as prime minister.
In his first public appearance since announcing he would step down, the PM said he is "determined" to carry on with the job of government and would not intervene in the Tory leadership race to succeed him.
"I'm determined to get on and deliver the mandate that was given to us, but my job is really just to oversee the process, he said while speaking during a visit to the Francis Crick Institute in London, adding that he's "sure" the outcome of the contest will be "good".
Asked whether he was angry about the way Cabinet colleagues had forced him out - particularly the "herd mentality" mentioned in his resignation speech - Mr Johnson said: "I don't want to say any more about all that.
"There's a contest under way and it's happened, and, you know, I wouldn't want to damage anybody's chances by offering my support.
"I just have to get on and, in the last few days or weeks of the job, the constitutional function of the prime minister in this situation is to discharge the mandate, to continue to discharge the mandate, and that's what I'm doing."
Former chancellor Rishi Sunak had long been considered a potential successor to Mr Johnson after remaining loyal to him throughout numerous controversies, but his resignation was one of those that started a snowball of walkouts which resulted in the PM saying he would stand down.
Sajid Javid was the first minster to quit last Tuesday, before dozens of others followed, and he delivered a stinging resignation speech in the Commons the following day, so it's no surprise the PM is not backing him.
Others who have remained loyal - such as Foreign Secretary Liz Truss and Transport Secretary Grant Shapps - may have hoped for the PM's support but Mr Johnson said offering it is not his job.
It was suggested by Number 10 sources on the day Mr Johnson announced he would leave Downing Street that the PM intended to stay in the job until the Conservative Party conference in October, almost three months away.
But many of his own backbenchers want him gone much sooner and even his newly appointed education secretary, James Cleverly, told ITV News last week that a successor could be in place "well before" the end of summer.
And it appears Mr Johnson may have accepted the strength of feeling within his own party about his aims to remain caretaker prime minister until autumn.
He provided a vague but much tighter timetable for his departure when speaking on Monday morning.
"I'm doing the last few days, weeks or how long it is - but the job of government has got to be carried on," he said.
Attorney general takes aim at benefits recipients while another leadership hopeful promises to help Tories win their seat at the next election - and they all promise tax cuts
A number of those hoping to replace Mr Johnson set out to Tory MPs on Monday why they should be supported to become prime minister.
Nadhim Zahawi, Mr Javid, Attorney General Suella Braverman delivered speeches, while Foreign Secretary Truss and Transport Secretary Grant Shapps released videos.
Ms Truss followed most of her rivals by promising to cut taxes and pledged to start doing so "from day one".
Mr Zahawi pledged to spend billions more on easing the cost-of-living crisis, saying he would remove VAT and green levies from energy bills, cut income tax and reduce business taxes.
Former health secretary Mr Javid said he would cut the National Insurance hike introduced in April by former chancellor Mr Sunak.
He said: "The assumptions that were made at the time, especially on tax revenue in coming years, turned out to be incorrect. That's because no one predicted the high inflation, and no one did across the world.
"But we now don't need that tax because the revenue situation has changed and given the impact on cost of living, given the impact NI (national insurance) changes can have on jobs, I think it's the right time to scrap it."
He also appeared to take a dig at Mr Sunak while delivering his speech, with a comment which seemed to refer to his former Cabinet colleague's social media video.
The ex-chancellor talked extensively about his family's background in a video which has been lauded for its high-level production, apparently put together in days, although many critics have suggested work on the film may have begun even before the PM announced his resignation.
"I'm not here to polish my backstory," Mr Javid said, "I don't have a ready made logo or a slick video ready to go."
Ms Braverman also promised to cut government spending. The attorney general pledged to remove VAT from energy bills and reduce corporation tax to attract investment, but she also took aim at UK welfare, which she says takes too much cash from the public purse.
She told ITV News "there are too many people in this country who are of working age, who are of good health, and who are choosing to rely on benefits".
Mr Shapps, while also offering tax cuts as part of his strategy to win the leadership race, avoided specific pledges in his social media video and instead promised backbenchers support with something they will want to secure perhaps more than anything else.
"I can help you win your seat," he said, as he appealed directly to the MPs whose nominations he needs to get into the competition's final round.
How long will it take to find Mr Johnson's replacement?
The timetable and rules of the leadership race, such as how many nominations a candidate will need to progress on to the next round, will be announced by the 1922 Committee of backbench MPs, following a meeting on Monday evening.
It's understood the committee wants the packed pool of candidates to be whittled down to two by next Thursday, so the MPs can make their nominations before they break for summer recess on July 21.
Bob Blackman, joint-executive secretary of the 1922 Committee, said the threshold for support to enter the Conservative Party leadership race is likely to be 20.
He told Sky News: "The view is that candidates to get on the ballot paper should demonstrate a broad swathe of support amongst Conservative MPs.
"So we're looking at a proposer, a seconder and either 18 supporters or possibly more supporters in order to reduce that list."
The threshold in the previous leadership contest was eight nominations, but it's being increased to 20 in a bid to speed up the selection process.
"We've got to slim down the list of candidates pretty quickly down to two," Mr Blackman said.
"And the one thing that we're committed to do is to achieve getting to two candidates by Thursday, July 21.
"That means that we'll hold a succession of ballots over the next few days in order to get to that position."
Ballots are likely to be held this Wednesday and Thursday and next Tuesday and Wednesday, he said.
He added: "The first ballot is likely to have a threshold of 10% of the votes, i.e. 36 MPs, supporting a candidate for them to go through to the second ballot. That once again is not confirmed yet, but I suspect that will be the case.
"After that we probably won't need thresholds because the list will shorten considerably."
Once there are just two candidates remaining, the decision will be passed to Tory members who will vote for the winner and whoever gets a simple majority will be crowned party leader and prime minister.
The final stage lasted a month in the previous leadership contest but may be even quicker this time around.
Which Tories are running to replace Boris Johnson?
It's mixed field of competitors - mainly on the right wing of the Conservative Party - which could be described as a David and Goliath race, with backbench minnows taking on Cabinet big beasts.
The likes of Rehman Chishti, a newly appointed Foreign Office minister largely unknown outside Westminster, are taking on forces such as former health secretaries Sajid Javid and Jeremy Hunt.
Here's a list of Tory MPs waiting in the starting blocks before the rules of the race are officially set out this evening:
Rishi Sunak, former chancellor
Nadhim Zahawi, current chancellor
Liz Truss, foreign secretary
Sajid Javid, former health secretary
Suella Braverman, attorney general
Grant Shapps, transport secretary
Kemi Badenoch, equalities minister
Tom Tugendhat, backbencher
Jeremy Hunt, former health and foreign secretary
Penny Mordaunt, trade minister
Rehman Chishti, Foreign Office minister