WASHINGTON: Republican Mike Johnson is in an increasingly nerve-racking fight to keep his gavel amid mutterings of rebellion on his right flank just three days before the US House of Representatives chooses its next speaker. Republican President-elect Donald Trump endorsed Johnson on Monday but even that may not be enough for the 52-year-old Louisiana conservative to win over the lower chamber of Congress, where the razor-thin Republican majority can afford almost no dissent. A chaotic 2023-24 session was marked by conservative anger over Johnson's handling of spending negotiations, as fiscal hawks lined up to attack him on grounds that he ceded too much to Democrats and was soft on the deficit. Johnson sought to project confidence in his job prospects on Monday, vowing to "get to work" on the incoming president's priorities in the new term. "Together, we will quickly deliver on your America First agenda and usher in the new golden age of America," he posted on X. "The American people demand and deserve that we waste no time." Trump's looming presidential inauguration raises the stakes of Friday's vote, since the House can do nothing until its leader is decided — including completing the certification of the 78-year-old Republican's victory, set for Monday. Assuming every member is present and voting on Friday — and that Democrats all back their leader, Hakeem Jeffries — Johnson can afford only one defection and still be reelected. But he already has one Republican "no" on the scoreboard, from Kentucky's Thomas Massie, while a handful of other conservative hardliners have been publicly open to a change at the top.