Paramount has taken its opposition to Netflix’s acquisition of Warner Bros. Discovery (WBD) directly to Congress, filing a letter with a House Judiciary antitrust subcommittee on Wednesday arguing that the merger is “presumptively unlawful.”

The filing came on the same day Warner Bros. Discovery’s board publicly rejected Paramount’s latest bid for the company, underscoring the ongoing battle for control of the Hollywood studio and streaming assets.

In the letter, Paramount’s chief legal officer, Makan Delrahim—who previously led the Justice Department’s antitrust division under President Donald Trump—warned lawmakers that the Netflix–WBD combination would “further cement its dominance in streaming video on demand.”

Delrahim criticized the notion, discussed during the subcommittee’s hearing on the streaming market, that Netflix competes broadly with platforms like YouTube and TikTok. He called such a market definition “tortured and absurd” and characterized it as “psychedelic antitrust,” arguing that free, user-generated content cannot substitute for premium, professionally produced shows and movies available on Netflix or HBO Max.

“It asserts, for example, that free, user-generated videos on YouTube and TikTok should be considered an adequate substitute for premium produced content,” Delrahim wrote. “This has no ground in market or legal reality.” He noted that Netflix itself has historically identified competitors only within the subscription streaming video on demand market, citing securities filings in which the company compares itself exclusively to other streaming services.

The subcommittee held a hearing on Wednesday examining competition in the streaming industry, with the potential Netflix–WBD transaction a central topic. While Paramount did not present in person, the company’s written comments were included in the official record. Lawmakers and expert witnesses repeatedly emphasized that the deal’s evaluation would hinge on how regulators define the relevant market.

Netflix did not immediately respond to a request for comment.

The proposed acquisition, announced last month, would see Netflix acquire WBD’s studio and streaming assets, while WBD’s cable channels would be spun off into a separate entity. Regulatory scrutiny is ongoing and includes not only the U.S. Justice Department but also European regulators and state attorneys general. While Congress holds oversight of antitrust enforcement, it does not have the authority to approve or block the transaction directly.

The filing raises fresh questions about whether regulators will adopt a narrow definition of the streaming market—focused on subscription-based services—or a broader, more inclusive approach that encompasses user-generated content, a debate likely to influence the fate of one of the largest deals in the entertainment industry this year.