State attorneys general have filed for a temporary restraining order and preliminary injunction in federal court in Sacramento to halt Paramount's proposed merger with Warner Bros. Discovery, fearing the deal could close as early as 22 July. The move follows a lawsuit filed the same day by California Attorney General Rob Bonta and 11 other state AGs, who argue the merger would let Paramount unlawfully harm competition in wide-release theatrical distribution, top film releasing and basic cable licensing—matters that carry weight given the deal has already cleared the US Department of Justice and awaits a decision from the European Union around the same date.

The AGs contend the merger would push market concentration to "presumptively unlawful levels" and warn that layoffs and content cancellations would begin immediately upon completion, making any later unwinding of the deal "extraordinarily difficult" if courts ultimately found it unlawful. They argue a pause would cause no real harm to the companies, noting the merger agreement's outside date extends to June 2027 if antitrust review continues, alongside a $7 million daily fee imposed on Paramount from 30 September 2026. Paramount has rejected the challenge as "fundamentally flawed" and vowed to defend the deal, with lawyer Daniel Petrocelli—who defeated a federal challenge to AT&T's Warner Bros. acquisition in 2018—representing the company.