In a rare symbolic rebuke to US President Donald Trump, the Senate on Tuesday adopted a resolution directing him to withdraw US military forces from hostilities with Iran.

The resolution was passed by a 50-48 vote, with four Republicans — Susan Collins of Maine, Lisa Murkowski of Alaska, Bill Cassidy of Louisiana and Rand Paul of Kentucky — breaking ranks with their party to vote in favour of the measure. John Fetterman of Pennsylvania was the sole Democrat to vote against it, according to The Guardian.

It was not immediately clear how the measure would affect the conflict, as the Trump administration has already reached an interim peace deal with Iran, Bloomberg reported.

The resolution had earlier passed the US House of Representatives by a vote of 215-208, with four Republicans joining Democrats in supporting the war powers measure. The Republicans were Thomas Massie of Kentucky, Brian Fitzpatrick of Pennsylvania, Warren Davidson of Ohio and Tom Barrett of Michigan.

Following the vote, Trump called the four Republican lawmakers “GRANDSTANDERS” and described their actions as “unpatriotic” in a post on Truth Social.

This is the tenth time since the beginning of the year that the Senate has passed a resolution seeking to limit Trump’s war powers over Iran that requires the US to cease hostilities against Iran unless Congress votes to authorise further attacks.

While the resolution is largely symbolic and does not carry the force of law, it reflects growing concern among a number of Republican lawmakers in both the House and the Senate over the conflict with Iran and the agreement Trump has reached to end it.

Senate Democratic leader Chuck Schumer called for the vote to compel Republicans to publicly state their position after several Trump allies expressed concern over both the war and the president’s agreement to end it, AFP reported.

“Republicans can complain about Trump’s war, his secrecy, and his disastrous deal with Iran all they want behind closed doors, but the only way to ensure this war ends once and for all is for Republicans to act,” Schumer said in a floor speech ahead of the vote.

Some Democratic senators, including Tim Kaine, also argued that the passage of a war powers resolution remains necessary, even after the US reached an agreement with Iran and amid continuing diplomatic engagement with Tehran, according to The Guardian.

“I think it’s a good time to have the vote to say, ‘Hey, if we’re really in a period of maybe some stability here, let’s not just allow it to start up again without Congress being involved in that decision,'” Kaine told reporters last week.