What happens if PM loses confidence vote
Sky News looks at how Conservative MPs could remove her as party leader amid growing discontent over her Brexit plan.
Wednesday 12 December 2018 18:19, UK
Theresa May is going to face a leadership challenge after 48 Conservative MPs sent letters to the 1922 Committee - triggering a vote of confidence.
Sir Graham Brady, the committee's chairman, said a ballot will be held between 6pm and 8pm tonight in the Commons.
"The votes will be counted immediately afterwards and an announcement will be made as soon as possible in the evening," he added.
:: Live updates from Westminster
:: The magic number
Mrs May's fate now hangs in the balance of the 1922 Committee - the parliamentary group of Conservative MPs.
The vote of confidence has been triggered because its chairman has received letters from 15% of Tory MPs - 48 of them at present - formally calling on the leader to stand down.
The process is completely blind, so only Sir Graham Brady knows how many letters have been submitted and by whom.
Several MPs publicly announced they had put in letters as part of a bid to unseat Mrs May in July, following the resignations of Boris Johnson and former Brexit secretary David Davis.
They remain on file, unless withdrawn.
The prime minister needs 158 votes - a simple majority of half the Conservative MPs plus one - to win. If they do, they get immunity from another formal challenge for a year.
:: What happens if Mrs May loses the confidence vote?
A date for the first round of the leadership election would be chosen by Sir Graham, in consultation with the prime minister.
Contenders to replace her will be nominated, but must get the backing of at least two other Tory MPs.
Depending on how many candidates there are, rounds of elections will be held, and the MPs with the fewest votes would drop out of the race one by one.
That all changes when there are two candidates left - Conservative Party members will have the final say in an open election.
Mrs May managed to win without going through this final phase, because her opponent, now Commons leader Andrea Leadsom, dropped out for suggesting being a mother made her better qualified.
If there is a contest, the winner will be announced by Sir Graham.
If parliament wants to get rid of the prime minister, it has to table a vote of confidence.
All 650 MPs would get the chance to vote formally on whether Mrs May should stay as leader or resign, with the expectation that a general election would follow.
:: The confidence ballot takes place between 6pm and 8pm tonight, with the result at 9pm. Follow live on Sky News