Historically tariffs would typically need to be approved by Congress, however when Trump came into power he argued he had the right to impose them using a 1977 law called the International Emergency Economic Powers Act (IEEPA).

In a six to three majority ruling, the Supreme Court has ruled that tariffs on products entering the US was not allowed under IEEPA.

President Trump reacted in a press conference calling the decision a ‘disgrace’, describing the case as important to him and a beacon of economic prosperity, adding it was a ‘terrible decision’.

The ruling was authorised by chief justice John Roberts, who was joined by two fellow conservatives and three liberal justices in the majority. In the ruling, Roberts wrote: ‘We hold that IEEPA does not authorise the president to impose tariffs.’

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