House Speaker John A. Boehner (R-Ohio) could once again face a conservative revolt and an attempt to remove him from the speakership. (Joshua Roberts/Reuters)

House Speaker John A. Boehner (R-Ohio) is bracing for what could be the toughest weeks of his speakership as several dozen conservatives in his party are threatening to topple him unless he is more ferocious with Democrats during the upcoming fiscal showdowns.

That internal feud has increased the chances that Washington, for the second time in two years, could stumble into a shutdown of the federal government.

The speaker’s lieutenants are openly girding for battle with the small but influential bloc of anti-Boehner conservatives who have signaled that if Boehner cuts any deal that they don’t like with congressional Democrats and President Obama, they could seek to remove him from the speaker’s post. It is a threat that Boehner and his allies are taking seriously.

“The people considering this are being totally irresponsible, but Boehner’s guys, we’re getting ready for whatever may come — not out of fear, but with exasperation about what some Republicans are willing to do to their own party,” said Rep. Peter T. King (R-N.Y.), who is part of the speaker’s circle of unofficial advisers.

Talk of unseating Boehner is not new, but this latest uprising is getting a jolt from the Republican presidential campaign, in which anti-establishment sentiment has driven two non-politicians, Donald Trump and Ben Carson, to the front of the pack.

Congress must pass a budget before Sept. 30, or it faces partially shutting down the government for the second time in two years. Here's how we got to another potential shutdown. (Jayne W. Orenstein/The Washington Post)

Last week, Trump led a rally outside the Capitol opposing the nuclear deal with Iran — enthusiastically attended by a half-dozen House Republicans who are Boehner critics — during which he took aim at Washington’s leaders, saying, “We are led by very, very stupid people.” The real estate mogul seemed to be directing his comments at the Obama administration, but GOP leaders fear that the heated rhetoric has shaken rank-and-file Republicans, too.

Influential Republicans say the current political environment has terrified dozens of lawmakers who support Boehner but fear that another vote to back the beleaguered speaker could lead to a backlash from conservatives in their districts.

“This is a continuation of the strange virus that’s running through the Republican Party, which I define as a weird form of right-wing Marxism where people are using Saul Alinsky-type tactics,” said Rep. Devin Nunes (R-Calif.), a Boehner confidant, likening the conservatives to the late radical activist from the 1960s.

Boehner’s official position is that he will remain atop the Republican caucus, which he has led for nine years, four as minority leader and almost five as speaker. “Navigating tough challenges isn’t new to this leadership team. The speaker is focused on the American people’s priorities and how we can accomplish them. He’s got wide support amongst our members, and he is not going anywhere,” said Emily Schillinger, Boehner’s spokeswoman.

The conservatives say their goal is to influence the policy outcomes of the next few months, rather than force a vote on Boehner.

“We don’t have a definite time frame. I’d say the question is still open about whether it will be done,” said Rep. Mark Meadows (R-N.C.), the second-term lawmaker who filed a resolution in July requesting a vote to remove Boehner. “At this point, I’m not aware of any member planning to do it. Our focus is on the legislative side of what we’re facing in the next 30 to 45 days.”

The first hurdle is funding the federal agencies, whose budget authority expires at the end of this month. Conservatives have latched onto this must-pass bill as a way to try to stop roughly $500 million in funding for Planned Parenthood, the women’s health services and abortion provider that has been enveloped by a heated debate over its fetal tissue program. The group says it sometimes harvests tissue for research, but some critics charge that it is illegally selling organs from aborted fetuses. Angry antiabortion conservatives say they will shut down the federal government if Planned Parenthood gets any money.

Democrats fiercely support the group and have already filibustered a bid in the Senate to end its federal funding.

Senate Majority Leader Mitch McConnell (R-Ky.) has explicitly said there is no chance of winning a standoff with Obama and Democrats over Planned Parenthood funding. Senate Republicans are trying to steer the debate to more committee investigations of the group’s behavior while keeping the government open.

But first the House has to act, and with 31 Republicans vowing to oppose any resolution that funds the government but does not cut off Planned Parenthood, Boehner’s leadership team would have to rely on Democratic support to pass the legislation.

These conservatives have not outlined a plan to overcome the Democratic support for Planned Parenthood, let alone how to build a two-thirds majority to override a presidential veto of legislation defunding the group. Some conservatives now articulating a shutdown strategy voiced regret after the 2013 shutdown, including Meadows, who told a local TV interviewer that Congress needs to “make sure it doesn’t happen again.”

That’s left some in leadership and their loyalists worried that their critics know the effort will fail and that they are setting a political trap for Boehner — anything other than a government shutdown would be portrayed as acquiescence to Democrats and reason for revolt.

Such a vote, formally known as a motion to vacate the chair, can be offered as a resolution by any House member.

Some Republicans close to Boehner say that the rebels have about 30 GOP votes to oppose the speaker, and more could follow if lawmakers feel political pressure at home.

Democrats have stayed mum about their intentions if such a vote took place — whether they would provide Boehner enough votes to remain in power or allow the chamber to descend into parliamentary chaos. Several Republicans supportive of Boehner said the main goal is to prevent Meadows or others from offering the resolution.

In recent days, several members of the Freedom Caucus, the leading coalition of conservatives, have met privately with members of the GOP leadership to go over legislative options, such as additional abortion-related measures, that the leadership hopes will assuage the group, according to people familiar with the discussions.

In one session, a member of the leadership read a list of bills that were ready. But prominent voices in the Freedom Caucus have been reluctant to rule out a shutdown, preferring to remain noncommittal as they try to build pressure on the leadership to take action.

Already, Freedom Caucus members are mulling whom to back if they topple Boehner. One name that has come up repeatedly in conversations, according to people who have participated: Majority Leader Kevin McCarthy. The 50-year-old Californian, No. 2 in the House leadership hierarchy, would signal a generational shift from the 65-year-old speaker but not an ideological one.

In past efforts, the anti-Boehner faction has never been able to coalesce around an alternative who could win a majority vote of the caucus — a secret ballot of all Republicans — and some conservatives acknowledge that they would look for a mainstream Republican who would give the conservative wing more attention and care.

“We’ll look for a speaker who will serve the conference, rather than the conference serving the speaker,” Meadows said when asked about the McCarthy chatter among his associates. “If Kevin could have that kind of inclusive debate, he could certainly find support.”

McCarthy’s inner circle is aware of the speculation, and several of his friends, who spoke on the condition of anonymity to talk candidly, say McCarthy is prepared to campaign hard for Boehner should the conservatives move. In the meantime, he has urged them to not indulge in palace intrigue.

In meetings this month with staffers and longtime allies, Boehner has said that he believes a vote to vacate the speaker’s chair is increasingly likely — and that he is going to fight, if necessary, to keep his position.

King, Boehner’s ally, said the opposition is so disorganized that the speaker should have put the Meadows resolution to a vote in late July and defeated it.

“We’re talking about how maybe 15 percent of our party in the House — 8 percent of the Congress — could remove the speaker. That sounds more like a banana republic than the American system,” he said.