Mike Johnson narrowly re-elected as House speaker with Donald Trump's backing

Republican Mike Johnson has narrowly won re-election to the House speakership on a first ballot, overcoming hard-right GOP holdouts after a tense standoff and buoyed by a nod of support from President-elect Donald Trump.

The uneasy scene brought an ominous start to the first day of the new Congress.

A small collection of hardline Republicans convened in the back of the House chamber, one by one declining to vote or choosing another lawmaker.

Johnson's face turned grim, acknowledging fresh turmoil and signalling trouble ahead for him as Trump returns to the White House and unified Republican control of Washington.

In the end, however, Johnson was able to flip two remaining holdouts who switched to support him and Trump called one of the dissenting Republican lawmakers from the golf course.

The final tally was 218-215.

Johnson, visibly relieved, vowed to "reject business as usual" in his first speech with the gavel.

"We're going to drastically cut back the size and scope of government," he promised.

Johnson's weak grip on the gavel has threatened not only his own survival but Trump's ambitious agenda of tax cuts and mass deportations as the Republicans sweep to power.

The tight vote tally laid bare the challenges he faces. Even backing from Trump himself, was no guarantee of Johnson's ability to stay in power.

The House Democratic leader Hakeem Jefferies attempted to push past the Republican tumult of the past two years, saying it was time to come together, put party politics aside "to get things done" for Americans.

What was once a ceremonial day with newly-elected lawmakers arriving to be sworn into office, often with family, friends and children in tow has evolved into a high-stakes vote for the office of House speaker, among the most powerful elected positions in Washington.

Vice President Kamala Harris was swearing in the senators.

While the Senate is able to convene on its own and has already elected party leaders — Senator John Thune as the Republican majority leader, who vowed in his first speech to keep the legislative filibuster in place, and Senator Chuck Schumer for the Democratic minority — the House must first elect its speaker, a role required by the Constitution, second in the line of succession to the president.

Trump had endorsed Johnson and was on the phone during the vote to secure the outcome.

"Mike will be a Great Speaker, and our Country will be the beneficiary," Trump posted on social media after the vote.

Congress has been here before, when it took Republicans nearly a week and 15 rounds of voting to elect Kevin McCarthy as speaker in 2023, a spectacle otherwise unseen in modern times.