House GOP leaders are scrambling to quell a quiet libertarian rebellion that threatens to block consideration of the Defense appropriations bill.

A small group of Republicans are holding the spending bill hostage until they get votes on several controversial amendments.

“We’ve conveyed to the whip team that we won’t vote for the rule if they don’t allow debate and votes,” Thomas Massie, R-Ky., said Friday. “We don’t need all the amendments to be allowed. We need at least one substantial amendment on three things: Egypt, Syria and NSA.”

Massie has two amendments before the Rules Committee: one that would defund military operations in Syria and one that would defund military operations in Egypt. Another leader in the Republican rebellion, Justin Amash of Michigan, has an amendment that would end funds for the National Security Agency’s blanket collection of telephone call records in the wake of Edward Snowden’s leaking of the program.

Rules Committee member Rich Nugent, R-Fla., has a similar NSA amendment, but the libertarian lawmakers say it insufficiently addresses the issue.

GOP leaders have been coming off a string of impressive victories lately — from passing the farm bill without a single Democratic vote to navigating a No Child Left Behind rewrite. But the Rules Committee postponed their meeting Thursday on the Defense appropriations bill, and leaders are still figuring out if they have the votes to squash the Republican revolt.

Majority Whip Kevin McCarthy, R-Calif., has pleaded with lawmakers in the group to not shoot down the rule and, consequently, shoot Republicans in the foot.

According to an aide to one lawmaker in the group threatening to vote down the rule, leadership has used “every tool in the toolbox” to block the amendments. The aide said they have faced a number of procedural roadblocks, from leadership saying their amendments legislate on an appropriations bill to having their amendments submitted to the Congressional Budget Office for a score. The aide said it has been a “concerted effort.”

But the lawmakers have cleared the hurdles, they say, and they want votes. They are drafting a letter calling for the opportunity to vote on their amendments, and they are seeking signatories.

On Friday, Jim McGovern, D-Mass., who will be controlling the Defense appropriations rule on the floor for the Democrats, said the Republican Conference is “just chaos.”

“They can’t seem to get their act together. So they got a problem,” McGovern said. “The Republican leadership long ago lost the ability to lead.”

McGovern, who is also a Rules panel member, said Democrats were initially told the Rules Committee was delaying its Thursday meeting on the Defense appropriations bill “out of deference to us” so Democrats could vote in the ranking member of the Natural Resources election, even though no Democrat asked the committee to delay the hearing.

“And then they delayed for another hour, and then they delayed it indefinitely and never told us why,” McGovern said. “We all know why: It’s because of these NSA votes.”

The Rules Committee plans to mark up the rule for the Defense appropriations bill at 5 p.m. on July 22, and Majority Leader Eric Cantor, R-Va., said Friday that the House will consider the DOD appropriations bill next week.

“We have been working with members all week and will continue to do so,” said Doug Heye, Cantor’s deputy chief of staff.

Rules Chairman Pete Sessions, R-Texas, said members and staff were taking the time to carefully review the bill and the amendments.

“It’s real simple: We’ve got a series of very important national security and public policy issues that deal not just with the Congress, but actual real life events that are occurring around the world,” Sessions said Friday. “And it is very apparent to us this is not just an appropriations bill, it’s one that we’ve got to look at broader ramifications.”

Sessions said the Rules Committee would take up the Defense appropriations bill “hopefully next week.”

He predicted the group holding up consideration would eventually come around.

“I think these guys are bright young guys,” Sessions said. “I know them and I know them well, and I hope to give them that confidence that they’ll vote for their favorite Rules Committee chairman’s rule.”