WASHINGTON — In his bid to become speaker of the House, Rep. Kevin McCarthy agreed to a number of concessions to secure the support of Republicans who originally opposed him. One was a rule change to allow just a single member to try to force him from office.

Under the new House rules passed Monday, only one member of Congress — Democrat or Republican — is needed to bring a “motion to vacate,” which forces a vote on removing the speaker. That would need only a simple majority of the House to pass to oust McCarthy.

Here’s what you need to know about how a motion to vacate would work and the history of the maneuver:

How does a motion to vacate work?

Under the newly adopted rule, any single member of the House could “offer a privileged resolution declaring the Office of Speaker vacant.” The term “privileged” here refers to a matter that has precedence over regular House business, meaning it is more urgent and must be brought to the House floor for a vote.

This is not confined to Republican members; Democrats could make the motion to vacate as well.

Procedural votes could be offered to slow down the motion, but when it does come to the floor, it would need only a simple majority of the House — or 218 members currently — to pass.

In theory, a small group of Republicans who want to force out the speaker could work with Democrats to reach the votes needed to remove the speaker.

Where did the motion to vacate come from?

The Constitution says nothing about ousting a speaker. In fact, “The House of Representatives shall chuse their Speaker,” is the only mention of the top job in the entire document. What the Constitution does say is that the House makes its own rules.

Most of those rules are based on “Jefferson’s Manual,” which the chamber adopted in 1837 as a guide for parliamentary procedure. “A Speaker may be removed at the will of the House,” the manual states. It was Speaker Joseph Cannon in 1910, however, who first used the motion to vacate as it is known now.

Back then the speaker was also chairman of the powerful Rules Committee. In a revolt against “Czar Cannon,” Progressive Republicans successfully stripped him of his spot on Rules. In a March 19 speech on the House floor, Cannon said he had only two options left: resign or “declare a vacancy in the office of Speaker.”

By offering the motion to oust himself, Cannon put his detractors on record. Republicans voted overwhelmingly to keep him in office. “Cannon, Shorn of His Power, Keeps Office,” read The New York Times headline the next day.

Has the motion to vacate been used recently? 

Republicans considered using the motion to vacate against their own leader, Speaker Newt Gingrich, in 1997 but decided against it.

The next case came in July 2015, when then-Rep. Mark Meadows of North Carolina, who went on to serve as President Donald Trump’s chief of staff, attempted to oust Speaker John Boehner.

While Meadows filed a motion to vacate, he said he hoped it would never come to a vote, and it never did. Boehner resigned as speaker a few months later.

The threshold for bringing a motion to vacate stayed at just a single member of Congress until 2019 when Democrats took the majority. That year, the House modified the rules to allow a vacancy resolution to be brought only “if offered by direction of a party caucus or conference” — a much higher bar.

The new rules package, passed Monday night by the House, changes the procedure for a motion to vacate back to how it had existed before, giving any member the power to raise it.