Boris Johnson has announced his resignation as Prime Minister but said he plans to remain as a caretaker until the next party leader is selected.
Mr Johnson gave resignation speech outside Downing Street before heading inside the iconic London property to be greeted by his family and other colleagues.
It marks the end of a tumultuous few days for the PM which saw his leadership rocked by dozens of resignations and a concerted effort to remove him by Conservative Party officials.
Announcing his intention to remain while a successor is chosen, party grandees and political opponents have come out to reject his attempt to "cling on" in No 10 until the autumn.
Mr Johnson also assembled a new-look Cabinet to replace the ministers who quit or were sacked since the political bloodbath began on Tuesday.
Speaking outside Downing Street, he said he regrets having to resign.
"I regret to not be successful in arguments and it's painful not to see through so many ideas and projects,” he said.
"I've agreed with Sir Graham Brady, the chairman of our backbench MPs, that the process of chosing that new leader should begin now and the timetable will be announced next week. And I've today appointed a Cabinet to serve, as I will, until a new leader is in place."
He added: “I want you to know how sad I am to be giving up the best job in the world. But them's the breaks.”
Details of the leadership election to replace Mr Johnson will be thrashed out next week but critics were already protesting about him remaining in No 10 while the contest takes place.
Former prime minister Sir John Major said it was "unwise and may be unsustainable", warning that the new Cabinet might not be able to "restrain" Mr Johnson in his final months in office.
Shortly before the speech, it was announced Shailesh Vara has been appointed as the new Northern Ireland Secretary. It comes after Brandon Lewis resigned from his post on Thursday morning.
In a tweet, Mr Vara described it as a “huge privilege to return to the Northern Ireland Office as Secretary of State”.
He also confirmed he has spoken with a number of Stormont party leaders including Michelle O’Neill, Sir Jeffrey Donaldson and Colum Eastwood, and said he plans to speak to others in the coming days.
He added that he had had a good conversation with Irish Foreign Secretary Simon Coveney.
"My immediate priority is the restoration of the Northern Ireland Assembly and Executive as soon as possible," he also tweeted.
How a dramatic day in Westminster unfolded: