The House on Thursday voted a second time to direct President Trump to end the war in Iran or seek explicit authorization to continue it, dealing him another bipartisan rebuke as he again ramps up military operations in the Middle East without approval from Congress.
Four Republicans joined Democrats in backing the measure, which does not have the force of law but is the latest evidence of disapproval on Capitol Hill with Mr. Trump’s handling of the conflict. Not long afterward, Republicans blocked a similar measure from consideration in the Senate, after key G.O.P. skeptics of the war either changed their stance or did not vote.
The House action came after the United States concluded its 12th consecutive night of strikes in Iran, following the collapse of a cease-fire that many Republicans had hoped would yield a diplomatic breakthrough to wind down the war well before they must face voters in November’s midterm elections.
The measure passed on a vote of 214 to 208. The Republicans who joined Democrats in favor were Representatives Tom Barrett of Michigan, Warren Davidson of Ohio, Brian Fitzpatrick of Pennsylvania and Thomas Massie of Kentucky. That was the same quartet that helped Democrats push through a similar war powers resolution last month.
“My position hasn’t changed,” Mr. Barrett, who is among the most politically vulnerable Republicans in the House, said in a statement after the vote. “Only Congress has the authority to authorize military action in Iran. I remain ready to work with anyone to eliminate hostile threats to our nation without getting us into another endless war.”
The resolution, sponsored by Representative Pramila Jayapal, Democrat of Washington, was among the final matters the House voted on before leaving Washington for a five-week summer recess. Many Democrats predicted that members of Congress would hear from voters during the break about how frustrated they are with the course of the war.
A Washington Post-Ipsos poll released last week found that only 29 percent of Americans support the war in Iran. A POLITICO poll found that Trump supporters who identified as “MAGA” voters said there were conditions to their continued support, with 37 percent saying they would only continue backing the conflict so long as prices for Americans did not rise. Global oil prices hit $100 a barrel on Thursday for the first time since May.
Representative Jason Crow, Democrat of Colorado, said that the waning public support would likely push more Republican lawmakers to speak out more forcefully against the Trump administration’s unilateral approach to the war.
“When we come back in September, I bet we have more people joining with us saying, ‘All right, let’s wrap this up,’ ” he said on Thursday.
The House vote underscored the growing divide between Republicans on Capitol Hill and the White House as the war in Iran drags on.
A growing group of Republican lawmakers has become more vocal about questioning the lack of congressional authorization or consultation, and also the administration’s failure to lay out a clear endgame. But Mr. Trump has shown no willingness to involve the legislative branch and little sign of winding down the campaign. Instead, he has escalated his bellicose language and asserted that he has unchecked power to continue the military operation.
Mr. Trump brushed aside Congress’s earlier rebukes last month, when the House and Senate both passed a similar measure, the first time since the conflict began in February that lawmakers voted to disapprove of it.
House Republican leaders are now pressing forward with a budget plan that would pay for the war, putting their members in the politically unappealing position of voting to finance an unpopular conflict that the Republican-led Congress has not authorized, and over which it has exercised little oversight.
In the face of Mr. Trump’s disregard for the congressional action, Representative Gregory W. Meeks of New York, the top Democrat on the Foreign Affairs Committee, said that he had begun the process to file a lawsuit against the administration for ignoring the resolutions.
“We have a situation where we’ve passed, now twice, war powers resolutions,” Mr. Meeks said in an interview on Thursday. “The president should not be able to get around this.”
In the Senate on Thursday, a similar resolution stalled after only one Republican, Senator Susan Collins of Maine, backed it.
Senator Bill Cassidy, a Louisiana Republican who previously voted to direct Mr. Trump to end hostilities or seek authorization to continue them, changed his stance. Senators Rand Paul of Kentucky and Lisa Murkowski of Alaska, two other Republicans who had backed similar efforts, did not vote.
It was the 12th time Democrats had forced such a vote, and they vowed to continue doing so as they implored Republicans to stop deferring to Mr. Trump and join the effort to wind down the war.
“As the war escalates even further, as more American service members are killed, as more civilians are killed, as oil and gas prices and other prices go up, this is an opportunity for this Congress to finally take responsibility,” Senator Chris Van Hollen, the Maryland Democrat who sponsored the measure, said before the vote. “We know the president has no respect for the law, but we have an obligation to our constituents. We should not duck that responsibility.”
Senator John Fetterman, Democrat of Pennsylvania, was the only member of his party to oppose it, in line with his past votes on the issue.
Mr. Cassidy said he had switched his position after multiple briefings by administration officials, though he still had concerns about the conflict.
“Now, do I approve how the war is being carried out? Not necessarily,” he said on Thursday. But he said he was not comfortable calling for an immediate withdrawal.
Senator Thom Tillis, a North Carolina Republican who opposed Thursday’s measure as he has previous such efforts, said that he might change his stance should the conflict continue to drag on. But he noted that presidents of both parties have at various times dodged the statute requiring consultation with Congress on military engagements.
“My rationalization for not really applying the War Powers Act earlier is all the games that have been played,” Mr. Tillis said. Given Mr. Trump’s formal notification to Congress on July 10 that hostilities with Iran had resumed, he said the president should have until Sept. 10 — the end of a 60-day window laid out in the war powers law — to act without authorization from Congress. (The 1973 law actually forbids the president from ordering American forces into a conflict without congressional approval unless the United States is under attack, but it provides a 60-day clock to terminate such an operation if he has not secured authorization.)
“The clock is ticking,” Mr. Tillis said.
But close allies of the president noted that he had repeatedly ignored what Congress had to say on the matter.
“Do you think he cares?” Senator Tommy Tuberville, Republican of Alabama, said on Thursday with a chuckle. “No.”