Citing concerns about the Iran war and the administration’s elevated defense funding request, Senate Democrats voted in lockstep on Tuesday evening to block a procedural motion to open debate on the 2027 National Defense Authorization Act, despite the bill passing out of the Armed Services Committee with bipartisan support.

The decision to block the start of debate on the NDAA — an annual must-pass bill that typically garners strong bipartisan support — is a rare step by Democrats signaling significant frustrations with the Trump administration’s ongoing war against Iran.

Sen. Jack Reed (D-RI), the top Democrat on the Armed Services Committee, said in a statement that he continues to support provisions in the bill, “but I cannot vote to proceed to a bill that enables an ongoing war against Iran that Congress never authorized and the American people overwhelmingly oppose.”

He said that Democrats are seeking amendments to “require accountability” for the war that have been rejected by Republicans. Reed added that Democrats also cannot support a significant increase in defense spending without more reliable accounting of the costs of the Iran war or “basic information” about it, and without a corresponding increase in non-defense spending.

Sen. Patty Murray (D-WA), the ranking member of the Senate Appropriations Committee, similarly cited the Iran war as a primary reason for her opposition to the bill.

“I will always do everything in my power to take care of our servicemembers and keep our country safe, but this bill authorizes President Trump’s absurd $1.5 trillion defense budget request while doing nothing to put an end to his disastrous war or prevent him from starting more costly conflicts abroad,” Murray said in a statement. “I refuse to endorse President [Donald] Trump’s obscene war budget, and I refuse to move this bill forward as Trump pushes our country deeper into a war the American people oppose”

Sen. Jeanne Shaheen (D-NH), the ranking Democrat on the Senate Foreign Relations Committee, said in a statement that it is “vital that we both pass the NDAA and that we constrain the President’s lawless and costly war against Iran.”

“With the President re-launching his self-defeating war, I voted against the motion to end debate on the NDAA, so we can continue to advocate for greater transparency and an end to this conflict,” Shaheen continued.

She said that amendments to reduce overall spending and withhold any congressional authorization for the Iran war failed along party lines during the closed-door committee markup of the NDAA.

Six progressive Democrats — Sens. Chirs Van Hollen (D-MD), Bernie Sanders (I-VT), Jeff Merkley (D-OR), Peter Welch (D-VT), Ed Markey (D-MA) and Elizabeth Warren (D-MA) — said they would vote against the motion to demand a vote on removing a provision on U.S.-Israel cooperation from the bill, and urged colleagues to do the same.

Though some anti-Israel voices have tried to paint that provision as the reason the Democratic caucus voted en masse against the bill, most Democrats did not cite that in their own statements on the bill.

Sen. John Fetterman (D-PA), the only Senate Democrat who has unreservedly supported the Iran war, was not present for the vote.

Republicans called the Democratic blockade dangerous to national security.

Sen. Chuck Grassley (R-IA) called the vote “SHAMEFUL” and said that the vote demonstrates that Democrats don’t take national security issues, which he described as the most important responsibility of the federal government, seriously.