The chorus of voices opposing Paramount Skydance's $110 billion takeover of Warner Bros. Discovery is growing louder. Why it matters: It will likely be up to state attorneys general and foreign regulators to challenge the merger, and there are indications that both groups are ready to act.Driving the news: Over 1,000 Hollywood professionals, including more than 75 Academy Award winners and nominees, on Monday released an open letter that said, in part:"The integrity, independence, and diversity of our industry would be grievously compromised" if the deal closes.Their argument should be well-received by California Attorney General Rob Bonta, whose department already opened an investigation. The other side: Paramount in a statement on Monday reiterated its commitment to full theatrical releases "ensuring creators have more avenues for their work, not fewer."Zoom in: Paramount needs regulatory approval from dozens of countries where it operates, plus big blocks like the European Union. U.K. antitrust regulators are set to launch an official probe into the deal after it finishes receiving public comments at month's end.The U.S. Justice Department is probing the merger, but antitrust experts don't expect it to object.The big picture: The DOJ could still sue to block the merger, but it becomes harder to do so now that Paramount has closed the deal. Case in point: A U.S. judge ‌ordered a pause on ​the $6 billion+ local broadcast merger between Nexstar and Tegna while he deliberates issuing an injunction in response to a lawsuit from DirecTV and several U.S. states.Just two weeks after the deal closed, Nexstar said in response to the order that the merger can't be fully undone.The bottom line: Longer approval processes overseas could give the state attorneys general more time to assemble their cases.