WASHINGTON — Sens. Mike Lee and Rand Paul have had enough.

The pair of libertarian-leaning Republican senators stormed out after a classified briefing with top Trump administration officials and declared they’d back a Democratic bill that would force Trump to go to Congress before any further military escalations towards Iran.

Lee (R-Utah) called the briefing “insulting and demeaning” to the assembled senators and the U.S. Constitution, saying it was “insane” and “unacceptable” that Secretary of State Mike Pompeo and other Trump officials only stayed for 75 minutes and repeatedly ducked questions from the assembled senators.

Paul (R-Ky.) wasn’t any happier, calling the briefing “absurd” and “an insult.”

Lee called the classified briefing to justify the rationale for killing a top Iranian general “probably the worst briefing I’ve seen, at least on a military issues, in the nine years I’ve served in the United States Senate.”

He said he went into the briefing undecided, but told reporters in the Capitol that the briefers’ inability or unwillingness to answer questions had convinced him to throw his support behind the measure, pending some changes he has worked out with Sen. Tim Kaine (D-Va.)

“I came out completely decided. I was convinced completely by the briefers that I must support the resolution,” Lee said. “The briefers told us a number of things that I found upsetting and disappointing and frankly disrespectful not just to us, personally — that doesn't matter — but to the Constitution itself.”

Just one day ago, Lee told VICE News that he was hesitant about supporting the measure because, in his eyes, the measure as written had "a lot of the findings of fact that really overstate things.”

But on Wednesday, Lee said he found it unacceptable that the briefers told Senators ”not to debate or discuss the appropriateness of any further military action against Iran because it might embolden Iran.”

“I find this completely inappropriate,” he said.

Paul took offense to the fact that the administration used the 2002 authorization for use of military force in Iraq to justify the drone strike that killed Iranian military official Qaseem Suleimani.

“That's the other thing that's insulting about this debate, is they're saying that the use of authorization resolution against Saddam Hussein justifies the killing of an Iranian General 20 years later in Iraq,” Paul said. “They essentially said that anything they do in Iraq is still justified by something voted on in 2002 for a government and a person who no longer exists on the face of the earth.”

Both Republicans have broken with their party on previous foreign policy issues. They worked with Democrats to pass a resolution aimed at ending U.S. involvement in Yemen’s civil war, and they were sharply critical of their colleagues now — and of Trump’s national security officials.

Paul said Pompeo and his crew preach diplomacy but haven’t tried it in good faith.

“The people around him don't seem to be very eager to have any kind of off ramps. They say we’re giving them off ramps, we’ll have diplomacy, but you have to have a conversation to get diplomacy started,” he said.

Even with their support, the measure is likely toothless — it may not pass the Senate, and even if it does Trump can just veto it. But it’s a political embarrassment for Trump to have two GOP senators blasting his administration so publicly.