The Supreme Court has struck down some of Donald Trump's most sweeping global tariffs, upending one of the White House's top policy priorities and injecting new uncertainty into global trade.
In a 6-3 decision, the justices in America's highest court said the law Trump used to impose some of his most significant tariffs did not authorise him to do so.
The ruling opens the door to potentially billions of dollars in tariff refunds, delivering a major victory to the small businesses and states that had challenged the measures.
The Trump administration had contended that the duties were justified under a law empowering the president to respond to national emergencies.
But lawyers for the challenging states and private firms said that the law used by the president to impose the levies made no mention of the word "tariffs".
