FIRST ON FOX: Rep. Matt Rosendale, R-Mont., will vote for a motion to vacate against House Speaker Kevin McCarthy, R-Calif., on Tuesday, he said in a statement to Fox News. 

Rosendale told Fox News in a statement that among the reasons for his vote are the fact that McCarthy worked with Democrats on the debt limit deal earlier this year, McCarthy not negotiating with the Senate over the NDAA, and McCarthy pushing a continuing resolution to avert a government shutdown over the weekend. 

"Instead of putting pressure on the Senate, Kevin McCarthy sold every American short when he brought forward a clean continuing resolution and suspended the rules of the House to pass a bill to continue Nancy Pelosi’s budget and Joe Biden’s policies," Rosendale said. "Which is why every single Democrat in the House, but one, supported the measure. Now, we are told that Speaker McCarthy has negotiated, in secret, with President Biden to provide additional funding for Ukraine, violating the trust and wishes of the Conference and most Americans. "

Rosendale added, "Unfortunately, Kevin McCarthy violated his promise to the American people and the Republican Conference by working against them repeatedly and supporting ploys to aid the Left. This demonstration of failed leadership is exactly why I plan on supporting the motion to vacate this afternoon."

HOUSE GOP MEMBERS SEEK TO EXPEL GAETZ AMID RENEWED THREAT TO VACATE HOUSE SPEAKER MCCARTHY

MCCARTHY SAYS ONLY FIVE GOP VOTES NEEDED TO FIRE HIM, DOESN'T EXPECT MUCH HELP FROM DEMS

Rosendale had not previously announced his position on a motion to vacate, though in comments to reporters he made clear he was entertaining the idea of ousting the speaker. 

Rep. Matt Gaetz, R-Fla., brought a "motion to vacate" against McCarthy to the House floor Monday. That forces the House to vote on whether to keep the speaker, and House GOP leadership teed up the issue for Tuesday afternoon. 

The vote on the motion to vacate is expected to be preempted by a "motion to table," brought by one of McCarthy's allies. If the motion to table succeeds, McCarthy would be safe, but if it fails, it would set up a live vote on whether to boot McCarthy from the speakership. 

McCarthy allies, meanwhile, argue that ousting McCarthy will put a pause on Republicans' efforts to pass appropriations bills and hand leverage to Democrats. 

With Republicans' extremely thin majority — and Democrats appearing united to vote to oust McCarthy — every vote will be key for McCarthy. 

It is possible some moderate Democrats would vote "present" or even vote to save McCarthy, helping the speaker overcome the defections from his own party. But House Democratic Caucus Vice Chair Ted Lieu, D-Calif., told Fox News flatly, "no" when asked if he expects any Democrats to vote to save McCarthy.