The feud between Hollywood writers and their agents has gotten even uglier with talent agency WME filing an antitrust lawsuit against the Writers Guild on Monday, alleging that the guild engaged in an illegal boycott and is abusing its power as a union. WME’s complaint against the Writers Guild of America alleges that the union abused its power by orchestrating a boycott designed to prevent WME from representing its members.

According to the lawsuit filed by WME, “the boycott to enforce their unlawful bans is nothing more than a ‘power grab’ masquerading as a legitimate exercise of union authority.” The complaint also contains a defense of packaging feses, which are collected by agencies for bundling talent and assembling writers, directors, and actors to work on a specific project.

Back in April, the Writers Guild told its members to fire their agents after the two sides were unable to reconcile over packaging fees and other agency practices. In the suit, WME defends the practice of packaging.

“Without packaging, some shows and films would never have been produced, and the writing opportunities these productions create would never have existed. Many writers have hired WME because of its packaging services. Writers want to benefit from meeting with, and being paired with, in-demand directors and actors. The ‘package’ of talent often enhances demand for the writer’s script and services and leads to the production of TV shows and movies that would not otherwise get made.”

The guild responded to WME’s suit, responding that “there is no merit to WME’s lawsuit, and the Guild will not be bullied into a bad deal.”

William Morris Endeavor, which is widely regarded as the largest talent agency in Hollywood, noted in the complaint that the Writers Guild “had expressly permitted packaging for more than forty years.” The guild pointed out that 1975, the William Morris Agency had sued the guild for antitrust violations after the WGA organized a campaign to end packaging fees.

The lawsuit against the Writers Guild comes only four days after the WGA rejected the proposal offered by the Association of Talent Agents. WME is now seeking a legal remedy for the dispute, as well as undetermined damages.

The Writers Guild of America filed a lawsuit against Hollywood’s top four talent agencies in April, which is still ongoing. Recently, CAA filed a motion to dismiss the lawsuit entirely. The outcome of this ugly dispute remains to be seen.