Ruling from court of international trade in New York comes after slew of lawsuits arguing president exceeded authority

A US trade court has ruled Donald Trump’s sweeping tariffs regime illegal, in a dramatic twist that could block the US president’s controversial global trade policy.

The ruling by a three-judge panel at the New York-based court of international trade came after several lawsuits argued that Trump had exceeded his authority, leaving US trade policy dependent on the president’s whims and unleashing economic chaos around the world.

Tariffs typically need to be approved by Congress but Trump has so far bypassed that requirement by claiming that the country’s trade deficits amounted to a national emergency. It left the US president able to apply sweeping tariffs to most countries in the world last month, in a shock move that sent markets reeling.