Lawmakers in the U.S. Senate were set to begin voting on Wednesday on ‌a bipartisan war powers resolution aiming to stop the military campaign against Iran and require that any hostilities against it be authorised by Congress.

The latest effort by Democrats and a few Republicans to rein in President Donald Trump’s repeated troop ​deployments, sponsors describe it as a bid to take back Congress’s responsibility to declare war, ​as spelt out in the U.S. Constitution.

“I do think it’s really important to put ⁠every member of Congress on the record about this,” Democratic Senator Tim Kaine of Virginia, a lead ​sponsor of the resolution, told a telephone press conference ahead of the afternoon’s vote.

“If you don’t have ​the guts to vote ‘Yes’ or ‘No’ on a war vote, how dare you send our sons and daughters into war where they risk their lives?”

Trump’s fellow Republicans hold slim majorities in both the Senate and House of Representatives and have blocked previous ​efforts for resolutions seeking to curb his war powers.

Republicans accused Democrats of playing politics with national security ​and said Trump had ordered only limited operations, such as the capture of Venezuelan President Nicolas Maduro in January, not ‌full-scale wars.

The U.S.-Israel war on Iran, which began five days earlier, is already more extensive, leading to damage in Iran, Israel and throughout the Middle East, and claiming its first U.S. casualties.

The House vote on the measure is expected on Thursday.

On Tuesday, Republican House Speaker Mike Johnson of Louisiana said he thought there were enough votes to ​defeat the resolution, describing ​it as an attempt ⁠to push something that could put U.S. troops in harm’s way and inspire Iranian forces.

“Imagine a scenario where Congress would vote to tell the commander-in-chief that ​he was no longer allowed to complete this mission. That would be a ​very dangerous ⁠thing,” he told reporters.

His remarks followed a classified briefing on the Iran conflict from top administration officials.

Even if the resolution passes the Senate, it must also pass the House and garner two-thirds majorities in both chambers to survive ⁠an ​expected Trump veto.

However, Kaine said that if the Iran conflict continued, ​he and the measure’s other backers could try again.

“Sometimes people will see things that concern them, and they’ll vote ‘No,’ but then ​later, as events continue to develop, they may vote ‘Yes,’” he said.