British Prime Minster Theresa May is fighting for her political life today as Parliament is set to vote on whether it has confidence in her leadership after the latest Brexit debacle.

The BBC posted an article today with exactly how the process works to overthrow the Prime Minister. As the leader of the conservative party, May depends on the support of the MPs, or Members of Parliament, and at least 15 percent of the Tory MPs — or 48 total MPs — must write a letter challenging her leadership, which has already occurred.

A secret ballot will be cast today between 1 p.m. and 3 p.m. on the East Coast of the U.S. to determine May’s fate.

To win and remain in power, May needs 159 votes, or half of her MPs, plus one. If that happens she’ll be immune to another challenge for a full year.

If she loses, there will be a new contest for leadership and she will be barred from participating.

There’s also a third option: May wins but only by a few votes, which might persuade her to resign, resulting in the aforementioned leadership contest.

Per the BBC:

How a leadership contest would work

The 1922 Committee – the organisation representing all backbench Conservative MPs – decides the procedure and sets the timetable for a leadership contest.

It is likely to follow the following format:

To enter the race, prospective leaders need to be nominated by two fellow Tory MPs.

If more than two wish to stand, MPs whittle down the field to two with a series of ballots where the lowest-ranking person is eliminated after each round.

Then it is time for ordinary party members around the country to vote. The two candidates would be expected to take part in debates to put their cases forward to members before the final voting deadline.

Candidates may withdraw between rounds, and if all but one withdraw, the one remaining candidate will become leader with no need for a vote from members.

Unless there is a general election, the winner of any Tory leadership contest would also become prime minister.