A group of hard-line Republicans joined with Democrats in executing a rare procedural gambit Wednesday that blocked a bill from being voted on in its current form, marking a small but embarrassing blow for GOP leadership.

Six Republicans joined all Democrats in supporting a Democratic-led motion to recommit for the Mining Regulatory Clarity Act, bringing the final vote count to a successful 210-204. Reps. Andy Biggs (R-Ariz.), Dan Bishop (R-N.C.), Eli Crane (R-Ariz.), Matt Gaetz (R-Fla.), Bob Good (R-Va.) and Anna Paulina Luna (R-Fla.) all voted “yes.”

A motion to recommit essentially sends a piece of legislation back to a House committee, blocking it from a vote on the floor. It is the minority party’s final chance to stop or amend a bill before the final vote.

Such votes are usually routine, mundane and predictable, with the minority party voting “yes” and the majority party voting “no.” A successful motion to recommit is exceedingly rare.

The legislation blocked Wednesday would make it easier for mining companies to conduct projects on public lands. The motion to recommit offered by Rep. Teresa Leger Fernández (D-N.M.) called for adding an amendment to the legislation that would bar any mining companies from operating on public lands if the Interior secretary finds that the organization’s parent company is “incorporated in, located in, or controlled by an adversarial nation.”

After the motion to recommit was agreed to, the House did not move forward with a final passage vote on the legislation.

The vote marked a defeat for GOP leadership, which put the bill on the schedule this week. House Majority Leader Steve Scalise’s (R-La.) office described it as a measure that was “supporting critical mining projects.”

It remains unclear why the hard-liners voted with Democrats to support the motion to recommit. The Hill reached out to the six Republicans for comment.

Wednesday’s vote was the latest procedural defeat GOP leadership has suffered this Congress. Members of the right flank have voted against rules — which set parameters for debate on legislation — a number of times this session, maneuvers that have blocked bills from hitting the floor for debate and final passage votes.

The successful motion to recommit comes as Speaker Mike Johnson (R-La.) faces increased scrutiny from hard-line conservatives after he cut deals with Democrats to fund the government, reauthorize the country’s warrantless surveillance powers and send aid to embattled U.S. allies overseas — including Ukraine.

Johnson’s support for the government funding bill in March prompted Rep. Marjorie Taylor Greene (R-Ga.) to file a motion to vacate to oust him from the top job. And this week, after votes on the U.S.’s spying powers and sending assistance to Kyiv, she announced that she will move to force a vote on her removal resolution next week — which is poised to fail amid mounting opposition.

Only two other Republicans — Reps. Thomas Massie (Ky.) and Paul Gosar (Ariz.) — have publicly come out in support of the ouster effort. Additionally, the top three Democratic leaders announced this week that they will vote to table the resolution if Greene forces a vote on it.