The leader of the US House of Representatives, Speaker John Boehner, has stunned fellow Republicans by saying he will resign from Congress at the end of October.
He will be giving up one of the most powerful jobs in Washington and his seat in the House in the face of hardline conservative opposition.
Mr Boehner, second in line to succeed the president and into his 13th two-year term, informed Republicans of his decision in a closed-door session.
It came one day after a high point of Mr Boehner’s congressional career, an historic speech by Pope Francis to the Republican-controlled Congress at Mr Boehner’s request.
A focus of conservatives’ complaints, Mr Boehner “just does not want to become the issue”, said Republican John Mica. “Some people have tried to make him the issue both in Congress and outside.”
Conservatives have demanded that any legislation to keep the government operating past next Wednesday’s deadline strip women’s health care provider Planned Parenthood of government funds, an argument rejected by more pragmatic politicians.
The dispute has threatened Mr Boehner’s speakership.
Some conservatives welcomed his announcement.
Tim Huelskamps said “it’s time for new leadership”, and Tom Massie said the speaker “subverted our Republic”.
“I think it was inevitable,” Mr Massie said. “This is a condition of his own making right here.”
But more mainstream Republicans said it would be a pyrrhic victory for the conservative tea partyers.
“The honour of John Boehner this morning stands in stark contrast to the idiocy of those members who seek to continually divide us,” said David Jolly.
The Senate was right to block a resolution that would defund Planned Parenthood. Now, stop these attacks—and don't shut down the government.— Hillary Clinton (@HillaryClinton) September 24, 2015
“The shutdown caucus as I call them has a small victory,” Mr Jolly said.
Mr Boehner’s decision removes the possibility of a damaging vote to strip him of his speakership, a scenario that grew more likely amid the conservative clamour over a shutdown.
Mr Boehner took over the speakership in January 2011.
He was first elected to the House in 1990 and soon established a strongly conservative record.
He was part of former Speaker Newt Gingrich’s leadership team when Republicans took over the House in 1995 for the first time in four decades but was ousted from his leadership role in the wake of the Republican GOP’s disappointing performance in the 1998 midterms.
He won a 2006 race to succeed Tom DeLay as the House’s No. 2 Republican when Mr DeLay stepped aside as majority leader. He took over as the top Republican in the House in 2007 after Democrats retook the chamber.
As speaker, his tenure has been defined by his early struggles to reach budget agreements with President Barack Obama and his wrestling with the expectations of tea party conservatives who demanded a more confrontational approach.
In 2013, conservatives drove him to reluctantly embrace a partial government shutdown in hopes of delaying implementation of the new health care law.