Nippon Steel and U.S. Steel sued President Joe Biden on Monday over his decision to bar them from joining forces, alleging that he had violated their constitutional rights to due process in a corrupt bid to obtain political support for his reelection campaign.

The suit alleges that it was a political decision to nix the deal and doing so violated the companies' due process.

The president said he was moving to protect national security in deciding the fate of the iconic Pennsylvania-based company, which became a contentious political issue in an election year.