The US House of Representatives has passed a resolution to sue President Barack Obama for allegedly exceeding his constitutional powers.
The 225-201 vote along party lines means House lawyers will now draft legal documents to launch a lawsuit.
Its supporters say Mr Obama exceeded his powers when he delayed an insurance deadline in his healthcare law.
The president himself has dismissed it as a waste of time. “Everyone sees this as a political stunt,” he said.
“If they’re not going to do anything, we’ll do what we can on our own,” the president added.
“And we’ve taken more than 40 actions aimed at helping hardworking families like yours. That’s when we act – when your Congress won’t.”
The action is reportedly the first time either the House or Senate has brought legal action against a president over the legality of his powers, although members of Congress have sued the president before.
Republicans in Congress have complained that Mr Obama has exceeded his constitutional authority on numerous occasions, in order to bypass Congress by issuing executive orders.
“This isn’t about Republicans or Democrats. It’s about defending the Constitution we swore an oath to,” Speaker John Boehner said during an impassioned debate in the House on Wednesday evening.
“Are you willing to let any president choose what laws to execute and what laws to change?”
In his six years in office Mr Obama has issued 183 executive orders, compared to 291 across George W Bush’s eight years and 381 for Ronald Reagan, according to a study by the American Presidency Project at the University of California-Santa Barbara.
But Republicans insist Mr Obama has selectively enforced laws duly passed by Congress, upsetting the balance of powers written into the constitution.