A lawsuit filed on Monday challenges the legality of US President Donald Trump's sweeping tariffs around the world. The Liberty Justice Center, a liberal-leaning pro bono legal center in Texas, filed the lawsuit with the US Court of International Trade on Monday on behalf of five owner-operated businesses allegedly harmed by the new tariffs. It is the broadest legal action yet against Mr. Trump's scaled-down tariffs. The lawsuit alleges that Mr. Trump has improperly used the International Emergency Economic Powers Act, a 1970's law, to implement much of his tariff regime and that the president is violating congressional authority. The Liberty Justice Center, which has national jurisdiction to hear cases involving international trade, is asking the court, which has national jurisdiction, to issue a broad order blocking the sweeping tariffs based on the IEEPA.