Tens of thousands of port workers in the United States are preparing to strike on Tuesday after failing to secure their demands during negotiations for a new labor contract, potentially disrupting international trade just weeks before the U.S. presidential elections.

The U.S. Maritime Alliance, representing employers at major ports on the East Coast and the Gulf of Mexico, confirmed that the Longshoremen’s Union is refusing to return to the negotiating table.

The alliance contacted the Labor Inspectorate on Thursday, urging for an “immediate court order requiring the union to resume discussions,” and condemned the unfair practices.