New York, Oct 3 (IANS): US Representative Matt Gaetz, a Republican, has moved ahead with his attempt to oust Speaker Kevin McCarthy from the leadership post, offering a motion to vacate the chair on the House floor.

It's not yet clear how the challenge to McCarthy will play out, but the effort represents the most serious threat to the California Republican's speakership to date, CNN reported.

A floor vote to oust McCarthy would require a majority vote to succeed.

Gaetz, who is from Florida and a frequent critic of McCarthy, has been pushing to oust the speaker by using the congressional mechanism to vacate the chair, which allows any one member the ability to call for a new speaker election, though the Republican Party leadership has a few options to stop or stall such an effort, Xinhua news agency reported.

According to local media reports, Republican conservatives have threatened to oust McCarthy over-relying on Democratic votes, as he did on Saturday to advance legislation staving off a government shutdown. Gaetz also cited the possibility of the House holding votes on sending aid to Ukraine as another reason to oust him.

"Members of the Republican Party might vote differently on a motion to vacate if they heard what the speaker had to share with us about his secret side deal with (President) Joe Biden on Ukraine," he said.

Speaking to reporters on the steps of the Capitol on Monday, Gaetz said: "If Kevin McCarthy works for Democrats and utilizes Democrats in order to keep power, that would be consistent with everything we've seen from him."

Earlier Monday, McCarthy declined to rule out the possibility of cutting a deal with Democrats to stay in power, though he said he hasn't spoken to Democratic Leader Hakeem Jeffries, of New York, about it. "I think this is about the institution," McCarthy said.