Eight members of the House of Representatives gathered near the Capitol on Thursday to demand a vote on U.S. war efforts against the Islamic State group in Iraq and Syria.

But as California Democrat Barbara Lee began to speak, a passerby with a two-horned megaphone declared war on them, making it impossible to hear speakers.

It was a fitting analogy for their efforts to prod congressional leaders to give an up-or-down vote on parameters for fighting the jihadi group.

Things took a turn as their heckler uttered a robotic “B,” “I,” “T,” “C,” “H,” an interruption so astoundingly rude that one of the lawmakers looked pained as they avoided laughing. Soon a police officer asked the man to roll away on his bicycle, which he did after telling the lawmakers, “Have this press conference, but realize I’m here for a reason, too.”

The press conference’s reason was easier to understand. The bipartisan group wants to tie up war funding unless their colleagues approve new Authorization for Use of Military Force (AUMF) legislation, and they’re pushing to attach amendments to an upcoming spending bill.

Unfazed by the interruption, Lee told reporters it was unacceptable for the current war effort to continue without its own AUMF. There has been “no action, no hearings, no debate, no vote” on an AUMF, she said, despite about $9.5 billion in cost to date. The military effort passed $7 billion in April, the Pentagon said. The CIA's aid to Syrian rebels at one point neared $1 billion a year.

Rep. Walter Jones, R-N.C., said “it is is not right and it is not fair to our men and women in uniform” that Congress allows President Barack Obama to cite a 2001 AUMF against al-Qaida to fight the Islamic State group. The jihadi outfit also called ISIS or ISIL actually is fighting the Syrian affiliate of the terror network behind 9/11.

Virginia Republican Rep. Scott Rigell, who represents a military-heavy district that includes Virginia Beach, said he believes the legal foundation provided by the 2001 AUMF is “crumbling.”

Many scholars say Obama cannot convincingly claim legal authority for the current war from the 2001 AUMF, or from a 2002 AUMF that justified the second U.S. war in Iraq and which Obama supported repealing. Last week, an active-duty soldier based in Kuwait filed a federal lawsuit alleging the war against the Islamic State group is illegal.

Defenders of Obama's claimed authority from the 2001 AUMF argue the Islamic State group came into existence as al-Qaida in Iraq and say Congress has implicitly sanctioned the war in previous spending votes.

The Constitution grants Congress the power to declare war, and the War Powers Resolution – enacted in response to secret expansion of the Vietnam War – limits use of force abroad to 60 days without congressional authorization, with an extra 30 days allowed for disengagement. The current war effort has gone 21 months without specific legislative authorization but with incremental increases in troop deployments.

The eight lawmakers indicated they approve of the lawsuit filed by Army Capt. Nathan Michael Smith, who says he supports fighting Islamic State terrorists but believes the effort currently is illegal. Smith’s lawyer David Remes says a positive outcome for the lawsuit could be repeal of the 2001 AUMF.

It’s unclear if the lawmakers’ proposed amendments to the National Defense Authorization Act will be allowed by the House Rules Committee. Press conference participant Rep. Jim McGovern, D-Mass., said he’s a member of the committee and believes the proposals are germane but that a similar amendment was not allowed last year after objections from House leaders.

If the amendments make it to the House floor, victory is not guaranteed for members who want to use spending restrictions to force an up-or-down AUMF vote with real-world ramifications.

In June 2015, the House soundly defeated a proposed resolution that would have ordered an end to the intervention without a new AUMF. It failed 288-139, and since then there’s been no serious effort to pass an AUMF. Some hawkish lawmakers say a proposal released by Obama last year would tie the military’s hands, while intervention-wary legislators argue the proposal would effectively do nothing.

Political gridlock isn’t keeping dissenters quiet, however.

“I want to remind [House Speaker Paul] Ryan that he is denying members of Congress our constitutional duty,” Jones said. Ryan and many reporters were nearby engaging with Donald Trump, the presumptive Republican presidential candidate.

McGovern said it’s wrong that “congressional leaders don’t even bat an eye” and the Obama administration sends “more and more troops” for an expensive, open-ended military campaign.

“If Congress is too damn chicken,” he said, “then we should bring our troops home.”

A respectful anti-war activist said “no boots on the ground in Syria, thank you very much!” after McGovern spoke. Obama last month approved deployment of 250 U.S. troops to Syria, adding to about 50 existing advisers to a Kurdish-led rebel alliance that were acknowledged in December. Nearly 5,000 U.S. military personnel are now in Iraq, up from a few hundred in June 2014.

“This mission had mission creep before it started,” said Rep. Thomas Massie, R-Ky. He pointed out some fellow Republicans had wanted to intervene in Syria’s civil war to help oust President Bashar Assad.

Massie said the most citizen engagement his office has seen came when Obama requested congressional approval to conduct air strikes on Assad – a request the president made in the face of strong political opposition and which he dropped as congressional opposition grew.

Reps. John Garamendi, D-Calif., Jan Schakowsky, D-Ill., and Peter Welch, D-Vt., also spoke at the press conference.

Schakowsky said the eight members “speak for a lot of others who aren’t here today.”