A group of U.S. consumers have sued Nippon Steel to block its proposed $14.9 billion purchase of U.S. Steel , saying the deal threatens to reduce competition and drive up prices for many products.

Nippon Steel and United States Steel 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 (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 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.