oris Johnson faced a growing revolt over suggestions he could hold onto as interim prime minister until October.
It came when three prominent conservatives Tom Tugendhat, Steve Baker and Suella Braverman launched their own leadership campaigns.
Senior Tory MP Tom Tugendhat was the last to announce that he will run as a candidate to replace Boris Johnson.
Writing in The Telegraph, Mr Tugendhat said: “I have served before – in the army and now in parliament. Now I hope to answer the call as Prime Minister again.
“It’s time for a clean start. It is time for renewal.”
The prime minister resigned at 12:30 a.m. after 60 members of his governmentincluding five ministers, resigned.
He said he would remained at number 10 until a new leader was found and chaired a meeting of his temporary cabinet at 3 p.m.
It is believed he could retain the lead in Downing Street until the Conservative Party conference later this year.
But the decision was rejected by several senior Tories, with some suggesting Deputy Prime Minister Dominic Raab should take over until Mr Johnson’s successor is found.
Bromley MP Sir Bob Neill said: “There is a serious question about how long an interim Prime Minister can remain in office if there are real concerns about whether the government can be fully and effectively staffed. We need to transition as much as possible. speed up .”
George Freeman, who stepped down as Science Secretary on Thursday morning, said: “Now Prime Minister has finally done the decent thing he needs to turn in the official seals, apologize to Her Majesty, allow her to appoint a janitor under whom ministers can serve, so that the Conservative Party can choose a good new leader.”
Sir John Major said Mr Raab should serve as acting Prime Minister until a new leader is elected.
The former Conservative Prime Minister, who took over when Margaret Thatcher was ousted by her party, said it was “unwise and possibly untenable” for the Prime Minister to remain in place.
In a letter to Sir Graham Brady, chairman of the 1922 Tory Committee, he said: “The proposal for the Prime Minister to remain in office for up to three months, having lost the support of his cabinet, his government and his parliamentary party , is unwise, and possibly untenable.
“In such circumstances, the Prime Minister retains the power of patronage and, more importantly, the power to make decisions affecting the lives of those in all four nations of the United Kingdom and beyond.
“Some will argue that his new cabinet will stop him. I just note that his previous cabinet couldn’t – or couldn’t.”
Conservative MP for North West Leicestershire Andrew Bridgen urged Sir Graham Brady to shorten the process to replace Mr Johnson.
He told the PA news agency: “I have spoken to Sir Graham Brady and urged him to shorten the election process for leaders where possible.
“I think we will have two candidates from the parliamentary party to present the membership for the recess. And that won’t be more than three or four weeks.
“So by the end of August we will have a new leader of the Conservative Party. So Boris Johnson’s estimate that he will still be prime minister in October is wildly inaccurate.”
The prime minister has replaced cabinet members who have left his government, but still has more than a dozen deputy minister positions to fill.
Labor leader Sir Keir Starmer also warned Johnson should not linger in Downing Street and threatened to call a vote of no confidence in the House of Commons if he refused to hand over the reins to an interim prime minister.
Sir Robert Buckland defended his decision to play a part in Johnson’s new cabinet, saying he was “here to help”.
The new Wales minister added that Johnson would not have the authority to do “new” things in government.
He said: “I felt it was good that I did that now. The issue about the prime minister and his character has been resolved. He no longer has the confidence of the Conservative Party. He is resigning. That’s right. But the affairs of the government continues. I’m here to help.”
Former Prime Minister Theresa May was asked if she would be willing to act as a janitor, but said: “I don’t think there will be an interim prime minister in the sense of someone else getting that role.”
Johnson promised in his resignation speech to serve until the new leader was in place.
He said: “I agree with Sir Graham Brady, the chair of our backbench MPs, that the process of electing that new leader should begin now and the timetable will be announced next week.
“And I have appointed a cabinet today to serve, as I will, until there is a new leader.”
He added: “I want to especially thank you, the British public, for the immense privilege you have given me and I want you to know that from now until the new Prime Minister is appointed, your interests will be served and the government of the country will continue.”