US lawmakers rejected hard-line conservative Jim Jordan's bid for speaker of the US House of Representatives for a second time on Wednesday, as the leadership vacuum paralysing Washington entered a 15th day with no clear resolution in sight.

The lower chamber of Congress has been in a tailspin since Republican speaker Kevin McCarthy was ousted by his party's far right on October 3 -- unable to address a looming government shutdown or war in the Middle East.

Jordan, an acolyte of scandal-engulfed Donald Trump, could only afford to lose four Republicans, but 22 of his colleagues rejected his candidacy in the second ballot -- two more than were against him a day earlier.

The Israel-Hamas conflict, a renewed push for aid to Ukraine and the threat of a government shutdown have dramatically upped the stakes, with Republican aides hoping the urgent need for Congress to respond would unite the fractured party.

But Jordan's centrist colleagues, already wary of his hard-right politics, voiced irritation over a concerted effort to whip extra votes for the 59-year-old former wrestling champion.

"Each day that passes without a speaker of the House is a national security risk," said Jordan supporter and California Republican David Valadao.

"I voted for the Republican Conference's nominee for speaker because we must get back to work, and we cannot do that until we have a speaker."

Jordan's second defeat compounded growing angst around the speaker's race and disarray within the Republican Party, with no immediate plans for a third vote and many -- including Valadao -- pushing to expand the limited powers of the largely ceremonial caretaker speaker. (AFP)