Twelve states have sued to block Paramount’s takeover of Warner Bros. Discovery, kicking off a high-stakes antitrust battle that could impede the media mega-merger.

California Attorney General Rob Bonta said the antitrust lawsuit, filed Monday in the Northern District of California, is necessary because the merger “would lead to higher prices, lower quality, and less content for film and television, harming movie theaters, basic cable distributors, and ultimately, audiences on every sofa and movie theater seat in the U.S.”

Paramount is prepared to fight the suit vigorously. The company has said the merger is lawful and “pro-competitive,” creating “a stronger challenger to dominant global streaming and technology platforms.”

Paramount has also pointed out that regulators in markets around the world have already approved the merger, including the US Department of Justice.

The DOJ’s review was clouded by allegations of political favoritism, given Paramount’s close ties to President Trump and members of his administration. “This reeks of corruption,” Sen. Elizabeth Warren said when the DOJ approved the deal in June.