Republican leader Kevin McCarthy has persuaded 15 more colleagues to support him in dramatic votes for House speaker, but still remains short of a majority.

He made extraordinary gains on the fourth day and the 12th and 13th ballots of a historic stand-off that is testing American democracy and the GOP majority’s ability to govern.

The switched votes from conservative holdouts, including the chairman of the chamber’s Freedom Caucus, put Mr McCarthy closer to seizing the gavel for the new Congress — but not yet able.

Republicans voted to adjourn until 10pm to try again.

“I believe at that time we’ll have the votes to finish this once and for all,” Mr McCarthy told reporters.

The stunning turnaround came after Mr McCarthy agreed to many of the detractors’ demands – including the reinstatement of a longstanding House rule that would allow any single member to call a vote to oust him from office.

Even if Mr McCarthy is able to secure the votes he needs, he will emerge as a weakened speaker, having given away some powers and constantly under the threat of being booted by his detractors.

But he could also be emboldened as a survivor of one of the more brutal fights for the gavel in US history.

Not since the Civil War era has a speaker’s vote dragged through so many rounds of voting.

The showdown that has stymied the new Congress came against the backdrop of the second anniversary of the January 6 attack on the Capitol, which shook the country when a mob of then-president Donald Trump’s supporters tried to stop Congress from certifying the Republican’s 2020 election defeat to Democrat Joe Biden.

At a Capitol event on Friday, some lawmakers, mostly Democrats, observed a moment of silence and praised officers who helped protect Congress on that day.

And at the White House, Mr Biden handed out medals to officers and others who fought the attackers.

“America is a land of laws, not chaos,” he said.

At the afternoon speaker’s vote, a number of Republicans tiring of the spectacle temporarily walked out when one of Mr McCarthy’s most ardent challengers railed against the GOP leader.

“We do not trust Mr McCarthy with power,” said Republican Matt Gaetz of Florida, as colleagues streamed out of the chamber in protest over his remarks.

One significant former holdout, Republican Scott Perry, chairman of the conservative Freedom Caucus who had been a leader of Mr Trump’s efforts to challenge the 2020 election, tweeted after his switched vote for Mr McCarthy: “We’re at a turning point.”

Another Republican holdout, Byron Donalds of Florida – who was repeatedly nominated as an alternative candidate for speaker, switched on Friday, too, voting for the Mr McCarthy.

On the 12th ballot, Mr McCarthy won the most votes for the first time 213. A 13th was swiftly launched, this time, just between Mr McCarthy and the Democratic leader, and he picked up one more detractor, to 214.

With 432 members now voting — including the dramatic return of Democrat David Trone who had been out for surgery — Mr McCarthy still fell short of the majority.

Six Republicans cast their ballots for a Republican colleague. Mr McCarthy allies were counting on the return of two absent colleagues to push him even closer to the majority in night-time voting.