The U.S. Court of International Trade ruled on Wednesday that U.S. President Donald Trump does not have the authority to impose his sweeping “Liberation Day” tariffs or his fentanyl-related duties against Canada and Mexico.

The ruling from the three-judge panel at the New York-based federal court marks the first major legal pushback to Trump’s broad use of tariffs to upend global trade.

The panel said Trump cannot wield tariffs on nearly every country through the use of the International Economic Emergency Powers Act of 1977.

The act, usually referred to by the acronym IEEPA, is a national security statute that gives the U.S. president authority to control economic transactions after declaring an emergency. Up until Trump’s return to the White House, it had never been used by a president to impose tariffs.

Wednesday’s ruling said “any interpretation of IEEPA that delegates unlimited tariff authority is unconstitutional.” It said “the challenged tariff orders will be vacated.”

It’s expected the White House will appeal.

The ruling combined two different cases that were pushing against Trump’s tariffs; one included five American small businesses specifically pushing against Trump’s worldwide tariffs, and the other stemmed from 12 states arguing against both the “Liberation Day” duties and the fentanyl-related tariffs.

At least seven lawsuits are challenging the tariffs.

Trump hit Canada with economywide tariffs in March after he declared an emergency at the northern border related to the flow of fentanyl. He partially paused levies a few days later for imports that comply with the Canada-U.S.-Mexico Agreement on trade.

Trump took his trade war to the world in April with duties on nearly every nation. The president walked back the most devastating duties a few hours later but left a 10 per cent universal tariff in place for most countries.