U.S. Rep. Jason Chaffetz, R-Utah has emerged as a surprise longshot challenger to House Majority Leader Kevin McCarthy to become the next speaker of the House.

WASHINGTON — House Republican turmoil is boiling over as leadership elections approach, with dissatisfied lawmakers casting about for new choices and a surprise longshot challenger emerging in the speaker’s race.

The upheaval reflects a caucus ever more divided in the week since House Speaker John Boehner stunned Capitol Hill by resigning under conservative pressure. And it comes as a long list of weighty and polarizing issues loom on Congress’ agenda, including raising the federal borrowing limit to avoid a market-shattering default, and paying the bills to keep the government running.

Rep. Jason Chaffetz of Utah, the brash 48-year-old chairman of the high-profile House oversight committee, intends to challenge the prohibitive favorite for speaker, Majority Leader Kevin McCarthy of California, Republican aides said Friday. Yet it’s not clear that the hardliners who ousted Boehner and view McCarthy with suspicion would flock to Chaffetz, given that as committee chairman he’s enforced leadership initiatives such as punishing lawmakers who buck the party position.

“It would be hard to replace John Boehner with someone who also kicks people off committees for their votes,” sniped Rep. Thomas Massie, R-Ky., who is backing another candidate, Rep. Daniel Webster, R-Fla.

That raises the prospect of more unrest — and potentially even more candidates — before votes for the new leadership team are cast Oct. 8.

“Until we decide that we’re going to function as a team instead of as a series of groups trying to enforce their agenda on the majority of the House, then we’re going to have this treadmill kind of a thing where we’re just walking faster and faster but not actually physically moving,” said Rep. Frank Lucas, R-Okla.

The well-liked McCarthy has been endorsed by Boehner, but some of the hardline conservatives who forced Boehner out immediately questioned whether his leadership would be any different. Their concerns were compounded when, a day after announcing his candidacy for speaker, McCarthy boasted that the House Benghazi committee can take credit for Hillary Rodham Clinton’s slipping poll numbers.

McCarthy backtracked, but it took him two days and the gaffe allowed Democrats to claim that the committee is a political witch hunt — not a fact-finding mission into the deaths of four Americans at the U.S. mission in Benghazi, Libya, as Republicans had long asserted.