Boris Johnson is to stand down as Conservative Party leader, but intends to carry on as prime minister until the autumn.
He is set to appoint new ministers to replace those who quit in protest at his leadership.
He intends to stay in Downing Street until a new Tory leader has been elected to replace him.
But some Tory MPs are urging him to leave as soon as possible to avoid government paralysis.
Former minister Sir Bob Neill told MPs there was a “serious question mark” over how long a “caretaker”
“Might it not be in everybody’s interest to speed up the transition as much as possible?,” he added.
It follows a dramatic 48 hours which saw dozens of ministers – including chancellor Rishi Sunak – resigning in protest at his leadership.
Mr Sunak’s replacement as chancellor Nahim Zahawi was among the ministers urging the PM to quit.
Mr Johnson resisted the calls until Thursday morning, when it became clear that he had lost the confidence of his MPs and that the government could no longer function.
Attorney General Suella Braverman and leading backbencher Steve Baker are the first Tory MPs to declare a leadership bid, with others expected to follow.
Less than three years ago, Mr Johnson won an historic landslide victory in a general election – but he has been dogged by controversy in recent months, including a fine for breaking his own lockdown laws.
The revolt this week was triggered by revelations about the prime minister’s handling of sexual misconduct allegations against former Deputy Chief Whip Chris Pincher.
BBC political editor Chris Mason said Graham Brady, the chairman of the 1922 Committee of backbench Tory MPs, has met the prime minister to tell him he has lost the confidence of the party.
Labour leader Sir Keir Starmer said the prime minister’s resignation was “good news for the country” but “should have happened long ago”.
Sir Keir accused the prime minister of “lies, scandal and fraud on an industrial scale” and said “those who have been complicit should be utterly ashamed”.
Is it sustainable for Boris Johnson to carry on as prime minister until the autumn?
His supporters will argue that offers some semblance of continuity and stability at a time where there’s not much of either.
Critics, such as Scotland’s First Minister Nicola Sturgeon, are already arguing it isn’t sustainable, given the huge number of vacancies in government.
Labour also think he should leave as prime minister now and there should be an interim prime minister until the autumn.
That argument will rage today.
And another will begin: who should be our next prime minister?
Liberal Democrat Leader Sir Ed Davey said it had long been clear Mr Johnson was “unfit to lead our country”, adding the “public won’t forgive the Conservatives for propping him up for so long”.
In a tweet, Scottish First Minister and SNP leader Nicola Sturgeon said there was a “widespread sense of relief that the chaos of the last few days (indeed months) will come to an end”.(BBC)