Family-run US cheese importer sues Trump over 50% Canadian tariffs, backed by the group that beat his 'liberation day' levies

New Jersey-based Gellert Global Group has asked the US Court of International Trade to rule the levies unlawful. It wants refunds with interest for every affected importer. The Liberty Justice Center, which filed the suit, says the White House exceeded its powers under Section 338 of the 1930 Tariff Act. The 50% duties hit some $20bn of Canadian goods after US-Canada talks broke down in August.

Co-chief executive Thomas Gellert: the tariffs 'disrupt those relationships overnight'.

The firm is also hit by Canada's retaliatory tariffs on American cheese it sells north.

The levies cover Canadian goods from wine and dairy to hockey sticks.