A leading hardline Republican said on Sunday he would move to oust House Speaker Kevin McCarthy for striking a deal with Democrats to avert a US government shutdown without the spending cuts demanded by the right-wing caucus.

"I do intend to file a motion to vacate Speaker McCarthy this week," Congressman Matt Gaetz told CNN. "I think we need to rip off the Band-Aid."

Gaetz is a leading figure within the House Freedom Caucus – a small group of hardline Republican legislators who had brought the government to the brink of shutdown with their refusal to adopt fresh federal funding without deep spending cuts.

The group was furious when McCarthy struck a stop-gap deal with Democrats late on Saturday to keep the government open for a further 45 days at current spending levels.

"I think we need to move on with new leadership that can be trustworthy," Gaetz told CNN, but said it was unclear that the group could actually remove the speaker, especially after McCarthy turned to Democrats to pass the bipartisan bill.

"The only way Kevin McCarthy is speaker of the House at the end of this coming week is if Democrats bail him out," Gaetz said. "Now, they probably will."

In addition to Democratic support, pro-McCarthy Republicans will work to prevent his ouster.

Republican Mike Lawler told ABC's "This Week" on Sunday that "the only responsible thing to do was to keep the government open and funded while we complete our work."

"By putting this motion to vacate on the floor, you know what Matt Gaetz is going to do? He's going to delay the ability to complete that work over the next 45 days," Lawler said.

If Congress had failed to keep the government open, the closures would have begun just after midnight (0400 GMT on Sunday) and would have delayed salaries for millions of federal employees and military personnel.

Among other immediate effects, the majority of national parks would have been shuttered to the public from Sunday.

The stop-gap measure buys legislators time to negotiate full-year spending bills for the rest of fiscal 2024. (AFP)