By Patricia Zengerle
WASHINGTON, June 23 (Reuters) - The U.S. Senate backed legislation on Tuesday directing President Donald Trump to halt U.S. military action against Iran, the latest rebuke of the Republican president from an increasingly restive Congress.
The Senate voted 50-48 in favor of the war powers resolution, which passed the House of Representatives early this month, reflecting growing concern even among some of Trump's Republicans about the unpopular conflict that began on February 28.
It was the first time both chambers of Congress had passed a resolution directing a president to remove U.S. armed forces from hostilities, as spelled out in the War Powers Resolution of 1973, more commonly known as the War Powers Act.
While likely to remain largely symbolic, the votes were a clear setback for Trump, who until recently enjoyed nearly full support from Republican members of Congress. Trump's Republicans hold slim majorities in both the Senate and House.
The Senate vote was nearly along party lines, with four Republicans joining all but one Democrat in favor. Two Republican senators did not vote.
It was not immediately clear how it would affect the conflict, as Trump's administration works to negotiate a peace agreement with Iran.
Under the War Powers Act, the measure does not get sent to the White House for Trump's signature. However, the White House has insisted the legislation is not constitutional and thus not binding.
Experts say it remains a contested legal question likely to be settled in the courts.
"The executive branch will likely ignore it on constitutional grounds, and it’s not clear who might have standing to sue to enforce it," said Scott Anderson, a senior fellow at the Brookings Institution and senior editor of the online legal publication Lawfare, adding that he expected someone would do so.
The resolution had also passed the House with slim Republican support. The tally there was 215-208 with four Republicans and every Democrat voting yes.
(Reporting by Patricia Zengerle; additional reporting by Richard Cowan; Editing by Sanjeev Miglani)
