WASHINGTON ― The influential conservative political group FreedomWorks is courting congressional support for an effort to debate the U.S. military role in Yemen, boosting critics of the war who aim to hold a House vote next week on cutting off U.S. support for the Saudi-led military intervention there.

“We’re involved, although our involvement is limited,” Jason Pye, the group’s vice president of legislative affairs, told HuffPost in a Friday afternoon email. “The reason we’re involved is because it’s a constitutional issue. Article I, Section 8 of the Constitution makes it clear that Congress has the sole authority to decide when the United States enters into a conflict, no matter what scale.”

The group is part of a broad coalition supporting a bipartisan proposal from Reps. Thomas Massie (R-Ky.), Walter Jones (R-N.C.), Ro Khanna (D- Calif.) and Mark Pocan (D-Wis.) that would end American military assistance for assaults by the Saudi-led coalition, which is fighting a rebel militia called the Houthis who receive support from Iran and former Yemeni President Ali Abdullah Saleh. (In a nod to Washington’s concerns about extremist militancy in Yemen, however, the resolution explicitly notes it does not seek to end U.S. counterterror operations there against groups like the local branch of al Qaeda.)

FreedomWorks’ participation alongside unlikely partners like Quaker anti-war activists is a fresh sign of how widely skepticism of the Saudi-led coalition has spread. The coalition has been accused repeatedly of war crimes and enabling extremism ― all while receiving American aerial refueling, weapons shipments and intelligence support approved by the executive and rarely debated in Congress.

Some libertarians see U.S. operations in the war as illegal since they were not explicitly approved by Congress, and top libertarian figure Sen. Rand Paul (R-Ky.) has long blasted the war as a prime example of American interventionism run amok. Mainstream politicians from both parties have condemned the coalition for violating international human rights agreements on matters like avoiding civilian casualties and its apparent disinterest in negotiations with the pro-Iran rebels.

Rights groups and congressional staffers see getting the House resolution to the floor as a way to establish awareness and a frank conversation about the U.S. responsibility for the situation in Yemen, which U.S. government lawyers have said may open up American officials to prosecution and which the United Nations calls the world’s largest humanitarian crisis.

Still, they face significant hurdles.

As of Friday, the bill only had two Republican co-sponsors (as well as 20 Democrats, mostly from the Congressional Progressive Caucus). Other more conservative lawmakers appear interested because it invites them to highlight what they see as executive overreach on foreign policy, Pye said ― but they have yet to speak out about it. Two other advocates for the legislation said they are heavily focused on the goal of winning public support from the powerful House Freedom Caucus.

And GOP leaders in the House who seek to defer to the Trump administration and avoid upsetting Saudi Arabia, the United Arab Emirates and other American partners invested in the war may attempt to prevent the vote from taking place altogether through arcane legislative maneuvers, said Kate Gould of the Friends Committee for National Legislation.

That raises the specter of more of the kind of Republican infighting and resentment that has driven congressional dysfunction in recent years.

“If they do [block it], then there would most certainly be an uproar,” Gould said.

The Trump administration has been sympathetic to the Saudi perspective on Yemen, which holds that the war’s opponents do not focus enough on the misdeeds of the Iran-backed rebels. The administration has drawn especially close to the kingdom despite the growing criticism of it on the Hill and abroad. On Friday, the State Department announced it had approved the sale of a $15 billion missile defense system to the Saudis ― part of a package President Donald Trump announced in May that top lawyers believe may be illegal.