Republican U.S. Senator Chuck Grassley introduced a bill on Thursday that would require congressional approval for new tariffs, the day after President Donald Trump unveiled sweeping new taxes on a vast array of imported goods.

For too long, Congress has delegated its clear authority to regulate interstate and foreign commerce to the executive branch," Grassley said.

Republican Sen. Chuck Grassley (Iowa) crossed party lines and teamed up with Democratic Sen. Maria Cantwell (Wash.) to introduce new legislation Thursday that would pare back President Trump’s tariff authority as GOP unease grows.

Few Republicans are eager to defend the president's tariffs, putting the party on the back foot for the first time in Trump’s new term.

The tariffs were fueling the strongest GOP pushback since Trump's inauguration, though Speaker Mike Johnson defended them