The Writers Guild of America has urged a federal judge not to intervene in the writers’ 20-month boycott of CAA and WME, saying the court lacks authority to do so.

The two largest agencies asked Judge Andre Birotte last month for an injunction that would force an end to the boycott.

The agencies have effectively acknowledged that the WGA has won the long-running dispute, but argue that the guild is punishing them by refusing to come to an agreement. The WGA has been fighting to end the practice of packaging fees and affiliated production, which the union says poses a conflict of interest and has suppressed writers’ wages.

One by one, the talent agencies have accepted the guild’s terms. CAA and WGA find themselves the lone agencies without a franchise agreement, as clients and agents flee for agencies that have signed the WGA deal.

CAA and WME have agreed to phase out the practice of collecting package fees, and have also offered to wind down their production investments to meet the guild’s demand that agencies own no more than 20% of affiliated production companies. But the WGA has said that their divestment plans do not meet the standard agreed by the other agencies.

In a bid to force the WGA’s hand, the two agencies filed motions in November asking Birotte for the injunction. The agencies argue, as they have all along, that the boycott is illegal under federal antitrust law because the WGA has leveraged its relationships with “non-labor parties” — showrunners and managers — to squeeze the agencies.

In their response filed on Friday night, the WGA’s attorneys invoked the 1932 Norris-LaGuardia Act, which forbids federal courts from issuing injunctions to break non-violent strikes.

“The Guilds’ conduct is no different from any other strike or work stoppage in which workers withhold labor until disputed conditions are satisfied,” the guild’s lawyers wrote. “The Guilds’ nonfraudulent, nonviolent efforts to persuade members to participate in this ‘boycott’ through enforcement of internal union rules are absolutely protected from injunction.”

The WGA also argued that CAA and WME are seeking special terms that were not afforded to rivals like ICM or UTA, and that the guild has a legitimate reason to want to limit the agencies’ ownership of production entities.

“The studios CAA and WME partially own are employers of the Guilds’ members,” the guild wrote. “A talent agent’s role is to represent writers in negotiations across the table from those very employers. CAA and WME’s interests in production studios mean they would effectively sit on both sides of the table when representing writers during negotiations — an inherent conflict of interest.”

A hearing on the motions is set for Dec. 18. Birotte has previously rejected the guild’s bid to postpone the hearing to February.

Birotte also rejected the guild’s earlier motion to dismiss the agencies’ lawsuit, finding a plausible claim that the WGA had abused its authority and was engaged in an impermissible “power grab.”