Not long after he blasted Donald Trump‘s administration for the briefing on Iranian general Qassem Soleimani’s assassination, Republican Sen. Mike Lee has agreed to support Democratic Sen. and presidential candidate Bernie Sanders‘ bill to freeze all funding for military action against Iran without congressional approval, CNN reports.

Sanders introduced the bill after the classified briefing that outlined the case for the drone strike that killed Soleimani. Like Lee, Sanders was critical of the lack of intelligence provided to support the administration’s claim that the Iranian general was planning an imminent attack on U.S. interests.

“They are justifying the assassination of Qasem Soleimani by claiming that he was planning ‘imminent attacks’ on hundreds of Americans in the region and yet they produced no evidence that would justify this claim, not even in a classified setting,” the 78-year-old politician said in a statement.

Lee’s decision to co-sponsor the bill makes him the first Republican to do so. Although Lee and Sanders don’t have much overlap in their political beliefs, they have teamed up before. Notably, they both supported a war powers resolution to end the United States’ support of Saudi Arabia’s war in Yemen — a bill that passed both the House and Senate before Trump vetoed it.

The pair issued a joint statement to CNN that addressed their recent approach to Iran.

“As United States Senators, we often disagree on many issues. But standing up for the Constitution is not about partisanship. The Founding Fathers were absolutely clear. They wanted to ensure that our country avoided needless conflict and they understood that presidential war-making would be harmful to our democracy.”

.@SenMikeLee

: "It is not acceptable for officials within the executive branch of government…to come in and tell us that we can't debate and discuss the appropriateness of military intervention against Iran. It's un-American. It's unconstitutional and it's wrong." pic.twitter.com/fVSE6b3EM0 — CSPAN (@cspan) January 8, 2020

The news comes in the wake of the non-binding War Powers resolution passing the House of Representatives. The bill received support from Independent Justin Amash as well as Republican Reps. Matt Gaetz, Thomas Massie, and Francis Rooney. Along with Sen. Rand Paul, Lee said he would support the resolution in the Senate.

Amash echoed Lee’s recent frustration with the Trump administration. The 39-year-old congressman expressed his belief that the Constitution provides Congress with authorization to declare war due give the American people a voice through their Senators and Representatives.

The Michigan Rep. claims that Trump’s decision to assassinate Soleimani without congressional approval is an abuse of power. He pointed to the constitutional requirement that every non-defensive military action has congressional authorization. Although Trump and his allies have suggested Soleimani was an imminent danger, they have yet to provide evidence to back such claims.