In a 45-minute roll call vote, the House moved to oust McCarthy as speaker.

The final vote was 216 to 210 in favor of Gaetz's motion to vacate, with eight Republicans joining Democrats.

"The office of speaker of the House of the United States House of Representatives is hereby declared vacant," said presiding officer Rep. Steve Womack.

It is the first time in U.S. history that the speaker of the House has been booted from the post, putting the chamber in unprecedented territory.

Republican rebels appear to have enough votes to remove McCarthy as speaker, given that Democrats joined them, though the vote is ongoing.

The House would be in uncharted waters if McCarthy is removed as speaker: A motion to vacate has never been used successfully.

But the chamber wouldn't be as paralyzed and chaotic as it was in January amid McCarthy's five-day, 15-ballot vote to win the gavel.

As part of a rule change after 9/11 to support the continuity of government, the speaker is required to deliver to the House clerk an ordered list of members who can act as speaker pro tempore in the event of a vacancy.

The person at the top of McCarthy's list will serve as interim speaker until a new one is elected.

If the motion to vacate is successful, the chamber could go right to another speaker vote -- and McCarthy's allies could put him forward again to reclaim his post.

But unlike in January, it's possible that the House could take up other business in the meantime: The chamber has a rules package, and the speaker pro tempore would have the authority to act as speaker until a new one is elected.

A roll call vote is underway on the motion to vacate, which will decide whether McCarthy will keep his gavel.

If successful, it will be a historic moment. The motion to vacate has only been used once before -- more than a century ago -- and failed.

It would take as few as five Republican defections to oust McCarthy as speaker, if all Democrats vote against him.

The House has canceled votes for the remainder of the week, according to Majority Whip Tom Emmer.

GOP sources say that Speaker Pro Tempore Patrick McHenry told party members during a Tuesday night conference meeting that the House is expected to recess until Oct. 10 -- and the plan is to hold a speaker candidate forum that day and then a vote for a permanent speaker on Oct. 11.

House Majority Leader Steve Scalise appears to be emerging from the closed-door conference meeting as the front-runner to replace McCarthy.

Both House Republican Conference Chair Elise Stefanik and Emmer indicated they're not running for speaker.

It's unclear if Scalise has enough support to succeed, but he spoke to reporters as he walked back to his office.

"We have a lot of work to get done, but I haven't made any formal announcement," Scalise, R-La., said.

"Clearly within our conference, we have a very tight majority," he acknowledged. "Getting things that done is going to be difficult in the tight majority. It's still will be so no matter who's going to be the next speaker, the challenges still remain, but I think the opportunity is there to continue moving forward."

Asked whether he is physically up to the job as speaker as he continues treatment for blood cancer, Scalise said, "I feel great."