Boris Johnson has resigned as leader of the Conservative Party and will step down as prime minister once his replacement has been found.
In a speech outside Number 10 Downing Street on Thursday, Mr Johnson announced that he is leaving after coming under enormous pressure from Cabinet MPs.
He said a timeframe for his departure would be made public next week.
He vowed to stay on in No10 until a new leader is found and pledged to give his replacement "as much support as I can" while admitting it was painful not to be able to see his ideas through.
"I have today appointed a Cabinet to serve, as I will, until a new leader is in place," he said.
How long can he stay on as a caretaker leader?
Mr Johnson is not known as "Teflon" without good reason. Throughout his three-year term in Downing Street, he repeatedly defied conventional wisdom by surviving scandals that would have brought down most other politicians.
Before the announcement, a No10 source said Mr Johnson had made clear to Sir Graham Brady, chairman of the 1922 Committee of backbench Tory MPs, that he wanted to stay on until the party conference in October. The process may not take that long. He did not say in his speech how long he expected to be in charge.
But opposition party leaders say he cannot continue to lead a government racked by a succession of scandals.
Labour leader Sir Keir Starmer said his party would use a House of Commons motion to attempt to oust him if the prime minister tried to hang on. “He needs to go completely,” Sir Keir said. “None of this nonsense about clinging on for a few months."
Will he stop being an MP?
In his 891-word speech watched by Tory loyalists, Number 10 staff and his wife Carrie Johnson and their nine-month-old daughter Romy, Mr Johnson did not say he would be resigning as an MP.
Instead, he pledged to work with a future leader. “To that new leader I say, whoever she or he may be, I say I will give you as much support as I can," he said.
When former Conservative prime minister Theresa May stepped down in 2019 there was speculation she would quit as an MP. But she chose to remain in politics and continues to sit in the House of Commons.
What happens now?
Any Conservative MP is eligible to run to replace Mr Johnson as party leader. The winner of the leadership race becomes prime minister, without the need for a national election.
MPs would take part in a series of votes to whittle down the leadership contenders to the final two, before the pair face a ballot of the 200,000 signed-up members of the Tory party.
The final two are expected to be, like Mr Johnson, staunch Brexiteers. Rishi Sunak, Sajid Javid, Penny Mordaunt, Nadhim Zahawi, Liz Truss and Dominic Raab are among the senior Tories expected to throw their names into the hat. Conservative MP Damian Green said Tom Tugendhat, chairman of the House of Commons foreign affairs select committee, will take part in the contest, and promised to support him.
The length of the contest is determined by the executive of the 1922 Committee in conjunction with the Conservative Party board. A new committee will be elected on Monday, allowing the timetable for the leadership race to be set.
How did it come to this?
After suffering 38 resignations from his government in the space of 24 hours, the Tory leader's tenure at 10 Downing Street was hanging by a thread on Wednesday evening, three years after he was elected prime minister.
The number of Tory MPs who quit government had risen to 59 on Thursday as Mr Johnson delivered his resignation speech to the nation.
Mr Johnson, known for his rule-breaking nature, has in recent months been dogged by scandals.
After weathering storms, his admission this week that he knew about a sexual allegation made against Chris Pincher when he appointed him to his government was too much to bear for even loyal Tory MPs.