Theresa May has announced she will stand down as leader of the Conservative Party on June 7, signalling the start of the race to replace her.
When will Theresa May leave office?
An emotional Mrs May announced outside No 10 that she will remain as UK Prime Minister until the Tory leadership contest is decided.
When David Cameron resigned following the referendum result in June 2016, the contest was originally planned to end in early September that year - but Mrs May was the last candidate standing and became Prime Minister on July 13.
In a joint statement, party chairman Brandon Lewis and the vice chairmen of the backbench 1922 Committee, Dame Cheryl Gillan and Charles Walker, said they hoped the new leader could be in place by the time MPs break for the summer - normally late July.
How will a leadership contest work?
Candidates must be nominated by two Conservative MPs.
If only one candidate comes forward, he or she becomes leader, but a coronation appears unlikely given the crowded field of leadership hopefuls already jostling for position.
The list of candidates is whittled down to a shortlist of two in a series of votes by Conservative MPs.
The final pair then go to a postal ballot of all party members, with the position of leader - and prime minister - going to the victor.
How long will it take?
Under the timetable set out by Mr Lewis and the 1922 vice-chairmen, nominations will close in the week beginning June 10.
The aim then would be to conclude the parliamentary stage of the process by the end of the month.
That would be followed by a series of hustings around the country, where non-members as well as members will have a chance to put their questions to the final two candidates, with voting to be wrapped up by the time of the summer recess.