Proceedings in the case, brought by five small businesses, come a day before tariffs are set to take effect.

Suit challenges president’s use of emergency economic powers law to impose tariffs.

Trump administration claims judiciary cannot review such ‘discretionary’ actions.

Suit argues that standards were not met for Trump to use emergency powers to impose sweeping tariffs

US courts assessing Trump’s tariff authority and reliance on 1977 emergencies act amid constitutional power debate.

Trump's reciprocal tariffs and trafficking-related duties were preivously struck down by a federal trade court, but that decision was put on pause.

Proceedings in the case, brought by five small businesses, come a day before tariffs are set to take effect.