Desperate to avoid another closure, Speaker John Boehner (R-Ohio) and his team would prefer to build bipartisan opposition to funding the group through a series of high-profile Congressional investigations. But, at this point, that seems unlikely to cut it with a bloc of House conservatives who have said they simply won’t vote for a large-scale spending plan that funds Planned Parenthood.

Funding runs dry Sept. 30, so Republican leaders have barely have a month to figure it out.

Many GOP aides are skeptical of using a funding bill to cut off the group’s government money, aware that the legislation would likely die in the Senate. And, even if Congress could broker a deal on Planned Parenthood, anything that cuts its government funding would likely be vetoed by President Barack Obama.

Instead, House GOP leaders would rather use’s Congress’ broad investigative powers to build an overwhelming case against the group, which they believe would allow them to hammer Planned Parenthood for months and put Democrats under enormous pressure to turn against the women’s health organization.

But conservatives – led by Rep. Jim Jordan’s (R-Ohio) Freedom Caucus – are girding for battle. They see the fight over Planned Parenthood’s money as one of the top legislative priorities of 2015, and they are eager to do anything to end government support. Jordan, in an interview, said an investigation is important, but the leadership must cut off the women’s health group’s money in any spending bill that comes up this fall. He wants to shift the money to community health clinics. And conservatives seem unafraid to shut down the government to achieve their objective —though they say that’s not their goal.

“I think we should stand firm and not fund Planned Parenthood, plain and simple,” Jordan said in an interview Monday. “If Barack Obama and Harry Reid think it’s more important that, Planned Parenthood, after what we know about them, gets taxpayer money, they think that’s more important than funding our troops, that’s a sad commentary on Obama and Reid.”

Jordan is not alone. Eighteen Republicans have come out publicly, saying they could not vote for any funding bill that doesn’t explicitly cut off funding. GOP leadership is not ruling out anything at this point. They say they might try to pass a short-term spending bill that defunds Planned Parenthood, in addition to a standalone bill, but many aides concede that end-game is unclear

“Leaders will make decisions in consultation with our members on the [continuing resolution] and other issues when they return in September,” said Kevin Smith, a spokesman for Boehner.

This fight will play out in a treacherous political environment for the GOP. The Republican presidential primary, not Congress, is setting the political agenda. And much of the presidential field has endorsed suspending funding to Planned Parenthood. At least two candidates — Sens. Ted Cruz (R-Texas) and Rand Paul (R-Ky.) — have said they will push measures to defund the group.

The stakes are very high for House GOP leaders. Conservatives are openly entertaining a vote to remove Boehner from the speakership. His top lieutenants, House Majority Leader Kevin McCarthy (R-Calif.) and House Majority Whip Steve Scalise (R-La.), will have to navigate the divide between Boehner and the right flank, with their political viability in the caucus on the line.

“All eyes of the country are going to be on the Congress, that to me is what counts,” Jordan said, when asked if he would support moves to remove Boehner if the Planned Parenthood issue isn’t resolved to his liking. “What matters is how do we handle everything in September. We have the Iran issue, Planned Parenthood issue, [spending caps], making sure we don’t continue [the Export-Import Bank], the highway bill and, when we get to the debt ceiling, making sure we get long-term savings.”

Almost everyone agrees that the pending showdown over Planned Parenthood’s funding is the most nettlesome among a slate of tough issues confronting Congress this fall. Government funding expires at the end of September, and the seven videos that allegedly show the group discussing fetal tissue from aborted babies has sparked nationwide outrage.

The most surefire way to cut off the group’s funding would be to insert language into a government-funding bill that explicitly prohibits money from being appropriated to Planned Parenthood. But such a measure would face insurmountable Democratic opposition in the Senate. Jordan, however, said he thinks senators will shift their opinion after more congressional debate. Furthermore, President Barack Obama, who is in his final 16 months in office, is almost certain to veto a bill that denied money to Planned Parenthood if it made it to his desk. Senior leadership aides in both chambers say a shutdown will not help the party achieve their goal of cutting off funding to the group.

Senate Majority Leader Mitch McConnell (R-Ky.) has been clear he thinks a shutdown would be a disaster for the party and he’s intent on avoiding one.

“We’ve been down this path before,” he said. “This is a tactic that’s been tried going back to the ’90s, frequently by Republican majorities that always have the same ending: that the focus is on the fact that the government is shut down, not on what the underlying issue that is being protested is,” he told reporters in August.

That’s why GOP leadership is trying to channel the outrage toward a congressional probe.

Boehner, a devout Catholic who has assembled a two-decade record of votes opposing abortion rights, is behind the broad investigation into the group that includes three House committees. The House Energy and Commerce Committee is investigating Planned Parenthood’s brokers and independent advisers. The House Judiciary Committee is probing the Justice Department’s enforcement of applicable laws. And the House Oversight and Government Reform is looking into the federal money trail.

Representatives from the three committees are meeting weekly to help ensure the investigation stays on track. A GOP leadership aide is making sure the committees don’t step on each other’s toes. None of the committees have scheduled public hearings for the fall.

Rep. Diane Black (R-Tenn.) said House GOP leadership has “assured her” that her bill to defund Planned Parenthood would get a vote.

“I’m looking forward to both the investigations and my bill coming to the floor for a vote,” she said. Black’s bill, which has more than 160 cosponsors, would put in place an immediate moratorium on government funding for Planned Parenthood for one year while Congress investigates the group.

Black, however, is opposed to shutting down the government to get her way.

“I’m not in the shut down government camp. That is not the way to get to the bottom of this issue, by shutting down the government,” the three-term lawmaker said. “It puts the president in charge instead of the legislature.”