The US supreme court will hear oral arguments on the legality of Donald Trump’s sweeping global tariffs on 5 November, a crucial hearing on the president’s aggressive economic agenda.
The court announced earlier this month that it would hear the case after a lower appeals court ruled that the US president had overstepped his authority by using a federal law meant for emergencies to impose most of his broad tariffs on the world.
Trump has sought to upend decades of US trade policy by imposing steep duties on imports from many overseas markets. He claimed the August ruling, the result of a challenge by a group of small businesses, “would literally destroy the United States of America” if allowed to stand.
Related: Most of Trump’s tariffs are illegal, federal court rules
The November hearing sets up a major test of the president’s use of executive power to drive through his economic and trade agenda.
The case was placed on a fast track by the supreme court, which begins its nine-month term next month. The court had also agreed to hear a separate challenge to Trump’s tariffs brought by a family-owned toy company, Learning Resources.
Trump invoked a 1977 law known as the International Emergency Economic Powers Act (IEEPA) to impose the tariffs, which are typically approved by Congress. The word “tariff” is not included in the law.
The US law “bestows significant authority on the president to undertake a number of actions in response to a declared national emergency, but none of these actions explicitly include the power to impose tariffs, duties, or the like, or the power to tax”, the federal appeals court in Washington DC said in a 7-4 ruling last month.
The tariffs have remained in effect during the appeal to the supreme court. A defeat would at least halve the current average US effective tariff rate of 16.3%, and could force the US to pay back tens of billions of dollars it has collected from the tariffs, according to Chris Kennedy, an analyst at Bloomberg Economics.
The supreme court has already granted the Trump administration approval for 18 consecutive requests for emergency relief.
