A US court invalidated Donald Trump’s “liberation day” tariff scheme, dealing a heavy blow to the White House that could throw the president’s global trade policy into disarray. 

The US Court of International Trade found on Wednesday that the president did not have the authority to introduce the levies using the emergency economic powers legislation he cited when he imposed sweeping tariffs on countries around the world last month.

The ruling represents a dramatic twist in the trade wars that Trump launched in the early months of his presidency, adding legal uncertainty to the financial and economic clouds that have surrounded the new era of American protectionism. Even if the ruling is appealed, it will for now embolden opponents of the tariffs in corporate America, foreign capitals and the US Congress who have been trying to persuade Trump to roll back the levies.