House Speaker Kevin McCarthy put his job on the line by enlisting the help of Democrats to pass a stopgap measure aimed at averting a government shutdown Saturday.

It is now considered a question of when and not if critics within his own party will move to have the Republican removed from speakership.

McCarthy faces a tough road ahead if he is involved in a fight to keep his job: House Republicans control only a narrow majority of the chamber, a dynamic that has left McCarthy with little room to maneuver and has given hardline conservatives outsized influence to exert pressure over the speaker.

Furthermore, to win over critics and secure the gavel earlier this year, McCarthy and his allies made a series of concessions to conservatives. One major concession was to restore the ability of any one member to offer what’s known as a motion to vacate the speaker’s chair – a move that can trigger a House floor vote to oust the speaker.

What is a motion to vacate and how would it unfold?

In practical terms, a motion to vacate the chair takes the form of a resolution to remove the speaker by declaring the speakership to be vacant. It is a rarely used procedural tool – and no House speaker has ever been ousted through the passage of a resolution to remove them. But threats over its use can be a powerful way to apply pressure to a speaker.

While any member can file a House resolution to remove the speaker, filing the resolution does not force a vote on its own. 

In order to force a vote, a member would need to come to the House floor and announce their intent to offer the resolution to remove the speaker. Doing that would then require the speaker to put the resolution on the legislative schedule within two legislative days — setting up a showdown on the floor over the issue.

How many votes are needed?

A vote on the resolution to remove the speaker would require a majority vote to succeed and oust the speaker from their leadership post.

What happens if the motion succeeds?

The speaker is required to submit a confidential list to the Clerk of people “in the order in which each shall act as Speaker pro tempore in the case of a vacancy,” according to the reference guide “House Practice: A Guide to the Rules, Precedents and Procedures of the House.”

In the event that McCarthy is no longer speaker, the number one name on the list will become interim speaker and the House will begin an election for a new speaker. In that case, the House will have to vote as many times as it takes to get someone to 218 votes, or a majority of those present and voting for a speaker.

Read more about the motion to vacate here.