Brexit campaigner Boris Johnson is considered a front runner in the contest to replace Theresa May after the British Prime Minister’s teary resignation announcement.
Mrs May will step down as Conservative Party leader on June 7, saying “it’s a matter of deep regret” that she failed to negotiate a Brexit deal.
An emotional Mrs May revealed her decision outside 10 Downing Street after meeting with Conservative Party powerbrokers to work out a timetable for her departure.
She will remain in the job until a new leader is chosen in what is expected to be a bitter contest given the internal animosity already surrounding Brexit.
Mrs May’s announcement follows months of calls from within her own party to quit over the UK’s bungled attempt to leave the European Union following the 2016 referendum on the issue.
For many colleagues, the final straw was her decision to revise her unpopular Brexit deal and soften her position on a possible second referendum.
“I have done everything I can to convince MPs to back that deal. Sadly, I have not been able to do so. I tried three times. I believe it was right to persevere, even when the odds against success seemed high,” she said in her resignation speech.
“But it is now clear to me that it is in the best interests of the country for a new prime minister to lead that effort.”
Mrs May will remain as leader until after a state visit from US President Donald Trump and D-Day commemorations at the start of June.
After that, the contest to replace her will formally start with a field of as many as 20 candidates whittled down to two in a final knock-out race.
Boris Johnson, 54, the face of the official Brexit campaign in 2016, is the favourite to succeed Mrs May and he thanked her for her “stoical service”.
Mr Johnson is said to be popular with grassroots supporters and is the bookmakers’ favourite while another confirmed contender, Foreign Minister Jeremy Hunt, has greater support among MPs.
The face of the official campaign to leave the European Union, Mr Johnson resigned as foreign minister in July in protest at Mrs May’s handling of the exit negotiations.
He has already indicated a hardline stance for the country to leave the European Union by the end of October, deal or no deal.
For many Conservative lawmakers, speed is of the essence to install a new leader 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.”
Mrs May showed a rare display of emotion in her departure speech, breaking down towards the end as she gave thanks for serving “the country I love”.
“I will shortly leave the job that has been the honour of my life to hold — the second female prime minister, but certainly not the last,” she said.
“I do so with no ill-will, but with enormous and enduring gratitude to have had the opportunity to serve the country I love.”