U.S. Republican Representative Jason Chaffetz, chairman of the House oversight panel, announced on Sunday he was running for speaker, a bid seen as a long shot that could still stir up the contest to replace John Boehner.
Representative Kevin McCarthy, currently the House majority leader, remains the favorite for the speaker position. But many conservatives have reservations about McCarthy and say he does not have enough votes to win.
Representative Daniel Webster, former speaker of Florida's House of Representatives, has also challenged McCarthy for House of Representatives speaker.
Chaffetz said many Republican lawmakers wanted a change in leadership. Republicans currently hold a majority in both houses of Congress.
"I've had enough members who have come and said, 'Please, Jason, do this. We don't want to fight internally, but realistically we can't vote to promote the existing leadership,'" he said on Fox News Sunday.
Chaffetz has investigated reproductive health provider Planned Parenthood and the Internal Revenue Service, groups conservatives despise, as oversight panel chairman. But he also alienated some lawmakers after he punished one conservative for failing to support leadership decisions.
McCarthy was criticized by many in his party after he made comments implying that a Republican-led probe into the 2012 attacks in Benghazi, Libya, was aimed at hurting Democrat Hillary Clinton's presidential candidacy. McCarthy later said his words were misinterpreted.
(Reporting by Emily Stephenson; Editing by Ros Russell)