Fighting back tears, Theresa May has announced she will quit, setting up a contest that will install a new British prime minister who could pursue a cleaner break with the European Union.
May's departure deepens the Brexit crisis as a new leader, who should be in place by the end of July, is likely to want a more decisive split, raising the chances of a confrontation with the EU and potentially a snap parliamentary election.
Her voice cracking with emotion, May, who endured crises and humiliation in her failed effort to find a compromise Brexit deal that parliament could ratify, said she would resign on Friday, June 7 with a leadership contest beginning the following week.
"I will shortly leave the job that has been the honour of my life to hold," May said outside her Downing Street official residence with her husband, Philip, looking on.
"The second female prime minister, but certainly not the last.
"I do so with no ill will but with enormous and enduring gratitude to have had the opportunity to serve the country I love," said the usually reserved May as she fought back tears.
May, once a reluctant supporter of EU membership who won the top job in the turmoil that followed the 2016 Brexit referendum, steps down with her central pledge - to lead the United Kingdom out of the bloc and heal its divisions - unfulfilled.
"It is, and will always remain, a matter of deep regret to me that I have not been able to deliver Brexit," May said, adding that her successor would have to find a consensus to honour the 2016 referendum result.
Jeremy Corbyn, leader of the main opposition Labour Party, said the new prime minister must hold an election to "let the people decide our country's future".
May bequeaths a deeply divided country and a political elite that is deadlocked over how, when or whether to leave the EU. The latest deadline for Britain's departure is October 31.
Most of the leading contenders to succeed May want a tougher divorce deal, although the EU has said it will not renegotiate the Withdrawal Agreement it sealed with Britain in November.
Boris Johnson, the face of the official Brexit campaign in 2016, is the favourite to succeed May and he thanked her for her "stoical service".
Betting markets put a 40 per cent implied probability on Johnson winning the top job.
For many Conservative lawmakers, speed is of the essence to install a new leader to try to break the Brexit impasse.
The governing party said it would move quickly to try to end the leadership contest before parliament breaks for a summer holiday, a so-called recess which usually falls in late July.
"The fight for the heart and soul of the Conservative Party officially starts now," said Andrew Bridgen, a pro-Brexit politician.
"We need a new PM as soon as possible and who that is will decide the future of our democracy, our country and the Conservative Party."
