U.S. House of Representatives Speaker John Boehner, who has repeatedly been challenged by the conservative wing of his Republican Party, plans to resign from the House at the end of October.

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

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U.S. Representative Kevin McCarthy of California, the No. 2 Republican in the House, is expected to be the leading contender to replace Boehner as speaker, Republican Representative Peter King told reporters.

In the wake of the news, Republican lawmakers said they would not shut down the government next week in an attempt to withhold funding from the women's reproductive health group Planned Parenthood, as some conservatives had threatened.

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Boehner was expected to speak to reporters shortly after 10 a.m. EDT about his resignation plan, CNN reported.

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 believed putting members through prolonged lea