The Tory leadership contest is now unofficially under way, with Boris Johnson’s resignation setting the wheels in motion for a new Prime Minister to take the reins.
The beleaguered PM finally made the decision to bow out as support for his premiership collapsed around him, with upwards of 50 MPs quitting government and party posts since Tuesday evening.
He will remain as Prime Minister until a successor is in place, expected to be by the time of the Conservative Party conference in October.
Mr Johnson’s departure fires the starting gun for a contest to replace him.
The exact timetable for this is agreed by the 1922 Committee and Tory Party HQ, with Conservative MPs and party members playing a decisive role in electing the next leader.
Tory MPs will whittle down the candidates to a final two through a balloting process, with party members then voting on who they would prefer.
In the meantime, Mr Johnson will remain as a caretaker prime minister.
But critics of the outgoing PM have suggested he should not be allowed to stay in office until the autumn.
Former prime minister Theresa May was asked if she would be prepared to act as a caretaker, but said: “I don’t think there’s going to be a caretaker prime minister in the sense of somebody else coming into that role.”
Possible contenders who have not yet announced their candidacy include Rishi Sunak and Sajid Javid, whose resignations from Cabinet on Tuesday triggered the mass exodus that ultimately crippled Mr Johnson’s leadership.
The PA news agency understands that Mr Javid, the former health secretary, is seriously considering running, as is Transport Secretary Grant Shapps.
Mr Shapps, who was key to the Prime Minister’s fight for survival during partygate, was among the Cabinet ministers telling Mr Johnson to stand down on Wednesday.
Some Tories have already made their ambitions clear. Attorney General Suella Braverman launched an unlikely leadership bid as support for Mr Johnson crumbled around him on Wednesday night.
Previously a loyalist to the departing PM, she told Peston on ITV that he had handled matters “appallingly” in recent days and that “the balance has tipped now in favour of saying that the Prime Minister – it pains me to say it – but it’s time to go”.
Ms Braverman, who was first elected as an MP in 2015, will be regarded as something of an outsider for the leadership given the party grandees already tipped to be running.
Prominent Brexiteer and former minister Steve Baker, a senior Tory backbencher, also confirmed on Thursday he is seriously considering putting himself forward for the top job.
He told Times Radio people are asking him to do it, and it would be “dismissive and disrespectful” if he did not heed expressions of support, though he said he regards the prospect with “something akin to dread”.
Foreign Secretary Liz Truss has made little secret of her leadership ambitions, with a series of high-profile interventions and photo opportunities in which she appeared to be channelling late PM Margaret Thatcher.
Despite being a fervent Johnson loyalist, she was nowhere to be seen as the Government crumbled around him.
She is now cutting short an official trip to Indonesia and will issue a statement shortly, sources close to her said.
Despite not routinely featuring among those tipped to take the PM’s place, Business Secretary Kwasi Kwarteng may have raised eyebrows with an intervention on Thursday morning, saying the country needs a leader who can “rebuild trust”, and that person should take charge “as soon as practicable”.
In a tweet, he made reference to his own trip to Teesside on Thursday, where he said he will be launching a “£400 million investment – a new offshore wind factory”.
“Westminster is a mess, but this investment – and those jobs – will outlast any PM. The wheels of Government must continue in the meantime,” he said.
Sir Robert Buckland, who has just been appointed the new Secretary of State for Wales, has declined to rule out running as Tory leader.
Asked on BBC Radio 4’s World at One programme whether he was considering throwing his hat in the ring, the former Justice Secretary said: “Who knows.”
However, Deputy Prime Minister Dominic Raab is not planning to stand to become the next Conservative Party leader, PA understands.