U.S. House of Representatives Speaker John Boehner, who struggled with repeated rebellions by conservatives during a tumultuous five-year reign as the chamber's top Republican, will step down from the speakership and leave the House at the end of October.

The Ohio lawmaker, 65, stunned Republican House members at a morning meeting on Friday with the announcement he will leave the top job in the 435-seat chamber and resign his seat effective on Oct. 30.

U.S. Representative Kevin McCarthy, 50, of California, the No. 2 House Republican, quickly became the leading contender to replace Boehner as speaker, lawmakers said.

Boehner's decision appeared to ease the threat of a government shutdown next week, as many Republicans said it would allow them to forge ahead with a "clean" spending bill that does not withhold funding from the women's reproductive health group Planned Parenthood, as threatened by conservatives who objected to the group's abortion services.

But House Democratic leader Nancy Pelosi, a longtime foe of Boehner, said the move would be "a distraction" during the spending debate and called his decision "seismic to the House."

Only the day before, Boehner, a Catholic, realized a longtime goal of hosting Pope Francis for an address to Congress and broke down in tears as he stood with the pope to greet crowds on the Capitol's West front.

Boehner brushed past reporters and did not answer questions as he left the Friday morning meeting, saying only, "It's a wonderful day."

PRESSURE OVER OBAMA

Boehner has faced constant pressure from conservatives who believed he was too willing to compromise with President Barack Obama and too likely to rely on Democratic votes to pass crucial legislation.

The approaching confrontation over government spending had raised the prospect of another possible challenge to his speakership by conservatives, something Boehner has beaten back several times before.

"I saw him recently and he looked weary. Understandably, he was tired," U.S. Senator John McCain, also a Republican, told reporters. "Sometimes we fail to appreciate that these are human beings with human emotions and lives to lead."

Boehner's plan had been to serve as speaker only through the end of last year, an aide said, but he changed his calculation when his No. 2 at the time, Eric Cantor, lost his seat last year in a Republican primary.

The aide said Boehner wanted to avoid a leadership fight and believed another bout of prolonged turmoil would do irreparable damage to the institution.

Representative Paul Ryan, a former U.S. vice presidential candidate, told reporters in a Capitol hallway that McCarthy would likely be the next speaker. Ryan said, "I don't want to be speaker."

McCarthy said in a statement that "now is the time for our conference to focus on healing and unifying to face the challenges ahead and always do what is best for the American people."

There was no immediate market reaction.

Phil Orlando, chief equity market strategist at Federated Investors, said: "The near-term news is good in that it suggests that Boehner is going to get a clean bill through as his last act as Speaker, but the question becomes what happens post-Halloween and who the new speaker is going to be."

The son of a bar owner and one of 12 children, Boehner is the only college graduate in his family. He grew up in Cincinnati and served in the U.S. Navy in 1969, then became a small businessman before launching a political career.

On Thursday evening as Boehner left the Capitol, he told two reporters - one from Politico and another from the Washington Post - that he had nothing left to accomplish after bringing Pope Francis to the Capitol, Politico reported.