Nippon Steel (JP:5401) and U.S. Steel (X) are trying to save their $14.9 billion merger deal by filing an opening brief in the U.S. Court of

Nippon Steel Corp. and United States Steel Corp. claimed former President Joe Biden unfairly prejudged their $14.1 billion merger and gave the companies no chance for feedback on a “sham” national security review before he blocked the deal.

Nippon Steel and U.S. Steel are asking a court to lift the block of their $14.9 billion merger. The steelmakers filed their opening brief in the U.S. Court of Appeals for the District of Columbia Circuit against former President Joe Biden and the Committee on Foreign Investment in the United States.

U.S. Steel and Nippon Steel laid out their case Monday that then-President Joe Biden hamstrung a national security review to justify blocking the companies’ merger. An opening brief filed in the U.S.

The decision has set off a rash of vituperative exchanges between Nippon Steel and Cleveland-Cliffs, whose earlier bid USS pushed aside in favor of the Japanese company’s more generous offer. Nippon Steel has since sued the US government and,