WASHINGTON ― A majority of the Senate supports limiting further hostilities against Iran despite opposition from Republican leadership and President Donald Trump, Senate Minority Leader Chuck Schumer (D-N.Y.) announced Tuesday.

The House last week approved a war powers resolution forbidding the president from attacking Iran unless there’s an imminent threat or Congress declares war.

Democrats are pushing to pass a similar measure in the Senate, saying the Trump administration failed to sufficiently justify the killing of Iranian military leader Qassem Soleimani without first seeking congressional approval. Democrats and a few Republicans have also questioned the administration’s initial rationale for the attack, which included a stated “imminent” attack on U.S. troops in the region.  

On Tuesday, Sen. Tim Kaine (D-Va.) announced that four Republican senators ― Rand Paul of Kentucky, Mike Lee of Utah, Susan Collins of Maine and Todd Young of Indiana ― had committed to vote with all 45 Democrats and two independents in support of his resolution limiting military action in Iran. The measure needs just 51 votes for passage.

“We now have a majority of colleagues who will stand strong for the principle that we shouldn’t be at war without a vote in Congress. And I’m going to keep working to get more, beyond the 51,” the Virginia Democrat said at a press conference.

Sen. Tim Kaine said four Senate Republicans have committed to vote for a resolution limiting U.S. military action in Iran.

Kaine, who has been vocal on war powers issues for years, said the measure may ultimately get the support of as many as 10 Republicans. However, he acknowledged it will not likely get the necessary additional Republican support to override a presidential veto. Trump is expected to reject the measure.

“That shouldn’t dissuade us from doing our job,” Kaine said, arguing that the resolution can send a message to Trump and perhaps even alter his behavior despite a veto.

Collins said it is important that Congress reassert its war-making powers under the Constitution. 

“The Kaine resolution would continue to allow the President to respond to emergencies created by aggression from any hostile nation, including Iran, and to repel an imminent attack by Iran,” the senator said in a statement.

Republican leadership, meanwhile, urged the Senate to reject the war powers resolution, warning that it would send a signal to Iran’s leadership that the U.S. was not prepared to defend itself abroad in the future. But unlike most bills introduced by Democrats, GOP leaders can’t block it because it is considered privileged and must receive a vote under the War Powers Act of 1973.

“President Trump’s strategy seems to have re-established deterrence,” Senate Majority Leader Mitch McConnell (R-Ky.) said in a floor speech on Tuesday. “But the Senate risks jeopardizing what we have gained with this strike if it ties the military’s hands and tells Iran we have no stomach for this.”

It’s unclear when lawmakers will vote on Kaine’s resolution given the upcoming Senate impeachment trial, which is expected to begin in earnest next week and last several weeks. Kaine said it’s possible the Senate could agree to do so before the trial gets underway, but that would require unanimous consent from the chamber. 

The Senate could also take up the resolution at some point during the trial, but that, too, would require cooperation from all senators.

The House is also expected to take up the Senate bill, which is slightly different, and vote to send it to Trump’s desk, according to Politico.