The US Senate on Tuesday approved a war powers resolution preventing Donald Trump from continuing the conflict with Iran, delivering the president a significant but symbolic rebuke over a conflict that has proven unpopular with the US public.

The resolution 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 with their party to vote in favor. John Fetterman, of Pennsylvania, was the sole Democrat to vote against it.

The measure, which passed the House of Representatives earlier this month, would require the president to seek Congress’s authorization to use military force against Iran. It comes after Trump dispatched JD Vance to Switzerland to negotiate a settlement that would resolve the conflict the US began alongside Israel in February.

Though the resolution does not carry the force of law, or require the president’s signature, its passage underscores the discontent among Republicans over a conflict that has grown deeply unpopular with voters ahead of the November midterm elections, in which Republicans will be defending their control of Congress.

A Reuters/Ipsos poll released on Tuesday found that a mere 23% of Americans believed the United States was stronger because of the war with Iran; nearly two-thirds thought any truce with Tehran was unlikely to last.

“Trump’s historic blunder in Iran will go down in the history books as one of the worst foreign policy forays America has ever made, or any country has ever made,” the Democratic minority leader, Chuck Schumer, said ahead of the vote.

“The American people have seen skyrocketing gas prices, soaring costs, and, tragically, the loss of 13 service members, and the wounding of hundreds more, and meanwhile, Iran took Trump to the cleaners.”