In response,Trump reimposed tariffs of 10 per cent under Section 122 of the 1974 Act, set to apply on Tuesday, with plans to raise them to 15 per cent. It lets the President impose tariffs up to 15 per cent for up to 150 days. It would however require Congress's approval to extend beyond the deadline. The court's ruling applies to Trump's so-called "Liberation Day" tariffs, but not individual tariffs he imposed on specific countries or products. He also said that he would use Section 301 to open investigations to "protect our country from unfair trading practices of other countries and companies."

The new 15 per cent tax rate raises questions for countries such as the UK and Australia which had agreed a 10 per cent tariff with the US, creating additional uncertainty.

Stephen Dover, chief market strategist, head of , said.

Wrapping up, Dover said the court's decision narrows the executive branch’s “emergency” tariff toolkit, without eliminating the tariff risk. “The Court left wiggle room for the Trump administration to reintroduce tariffs consistent with the law and constitution.” For investors, Dover believes that the removal of IEEPA tariffs is good news. “It is a form of fiscal easing, which will likely boost purchasing power and growth across many sectors of the economy,” he said. “It should lessen price pressures and therefore ease the Fed’s dual-mandate dilemma." While tariff uncertainty has returned through legal pathways, the scope of new tariffs in size and breadth has probably been curtailed by the ruling.