The complaint was filed in the US Court of International Trade by 22 state prosecutors and two Democratic governors.
It mirrors a previous lawsuit filed by a smaller group of 12 state attorneys general over tariffs Trump introduced last year under the International Emergency Economic Powers Act (IEEPA).
Those duties, which started at 10% but hit more than 40% for goods from some countries, kicked off a flurry of trade negotiations as countries pushed to secure lower rates in exchange for promises of investment and other changes.
After the Supreme Court rejected those tariffs last month, the White House announced the new Section 122 global levy at a rate of 10%. That law allows the president to impose tariffs up to 15% for 150 days without Congress, under certain conditions.
US Treasury Secretary Scott Bessent said recently that the US was “likely” to raise the rate to 15%, as Trump had threatened, this week.