A ruling by the Supreme Court striking down President Donald Trump's use of the 1977 International Emergency Economic Powers Act, or IEEPA, to impose broad global tariffs would eliminate a favourite cudgel to punish countries that draw his ire on non-trade political matters.

The court, whose 6-3 conservative majority includes three justices nominated by Trump in his first term, takes up the challenge on Wednesday, which was launched by small business groups and several states. It's not clear how quickly the top court would release an opinion.

Trump is the first president to invoke this statute — which has often been used to apply punitive economic sanctions on adversaries — to impose tariffs. WATCH | Court case comes with much uncertainty in U.S.-Canada trade talks:

Future of U.S. tra

See Full Page