London - Britain's ruling Conservative Party will decide the country's next prime minister in late July - a contest that will bring in a new leader who could pursue a cleaner break with the European Union.
Theresa May resigns as the party's leader on Friday, having failed to deliver Brexit on schedule or find a way to get parliament to approve her exit plan.
May's announcement does not trigger a parliamentary election. So far, 11 candidates are running to replace her. The winner of the contest will become party leader and prime minister.
Here is how that process, which is overseen by an internal party group known as the 1922 Committee, is expected to work:
Candidates putting themselves forward for the leadership must be backed by eight other Conservative lawmakers. This is higher than in previous contests, after the committee made rule changes designed to cull weaker candidates.
A call for candidates will be made on Friday. Nominations will be received from 0900 GMT on June 10 and until 1600 GMT on the same day.
BALLOT OF LAWMAKERS: From June 13
Conservatives lawmakers then hold several rounds of votes to whittle down the number of candidates. Each time, they vote in a secret ballot. They are allowed to vote by proxy if they are not available to vote in person.
Voting will take place in a room in parliament, which will be set up with voting booths. The colour of the ballot paper is chosen the day before and will be different for each round. Completed papers will be placed in a metal ballot box.
The first round of voting will take place between 0900 GMT and 1100 GMT on June 13, with the result expected to be announced around 1200 GMT. Any candidate with 16 votes or fewer is eliminated. If all candidates have more than 16 votes, the one with the fewest votes is eliminated.
The second round will take place on June 18, between 1400 GMT and 1600 GMT, with the result due around 1700 GMT. Any candidate with 32 votes or fewer is eliminated. If all candidates have more than 32 votes, the one with the fewest is eliminated.
Further ballots are scheduled on June 19, between 1400 GMT and 1600 GMT and on June 20, between 0900 GMT and 1100 GMT. Voting continues until two candidates remain, so further rounds will be held if necessary.
The 1922 Committee will host two rounds of hustings in parliament for candidates, the first on June 11 and 12, ahead of the first vote, and the second on June 17.
MEMBERSHIP VOTE: Concludes in week beginning July 22
The final two candidates are put to a postal ballot of the wider Conservative Party membership, with the winner named the new leader.
The party said it wanted to complete this stage in the week beginning July 22.
The party has around 160,000 members. It said the first membership hustings event would take place on June 22.
WHO IS PRIME MINISTER DURING THE CONTEST?
In her resignation speech, May said she would serve as prime minister until the leadership contest was concluded. She will also remain acting Conservative Party leader during that time.