The proposed $110 billion merger of Paramount and Warner Bros. Discovery always was going to face a rocky road toward regulatory approval, but a group of Democratic lawmakers has raised a new set of concerns.

Six U.S. senators sent a letter Wednesday to Federal Communications Commission chairman Brendan Carr, arguing that the significant amount of foreign money involved in the planned WBD takeover by Paramount, the CBS Sports parent company, “raises national security alarms.”

Paramount previously said in an FCC filing that 49.5% of the merged entity of Paramount and WBD, the parent company of TNT Sports, would be owned by foreign investors. In addition, about 38.5% of that equity would be owned by sovereign wealth funds of Abu Dhabi, Qatar, and Saudi Arabia.

“The scale, concentration, and scope of this proposal raise serious questions,” wrote the senators. Helping lead the group of six lawmakers on this front is Sen. Maria Cantwell (D., Wash.), the top Democrat on the Senate Commerce Committee, which oversees the FCC. “Foreign governments hostile to a free and independent press could exert unprecedented influence over a media conglomerate vital to American journalism and culture.”

Current federal statutes prohibit more than indirect foreign ownership of TV or radio stations exceeding 25%, and the Paramount deal seeks an exception to that statutory cap.