The Independent Workers of Great Britain (IWGB) has issued formal legal claims against Rockstar Games, which it has accused of union busting. The Grand Theft Auto VI developer last month fired dozens of employees who were organizing.

The IWGB said in a statement it made several attempts to meet with Rockstar with the aim of resolving the situation through negotiations, but claimed the studio rebuffed the union. It’s now looking to take the matter before a court. “We have now issued formal legal claims against Rockstar on behalf of the claimants,” the IWGB said. It added that it believed the firings “amount to victimization and collective dismissal linked to trade union activity.” The union previously said that all of those who Rockstar fired were members of the members of an IWGB Game Workers Union Discord server.

Alex Marshall, the president of IWGB pledged that the union will “mount a full legal defense with our expert group of caseworkers, legal officers and barristers. Employers like Rockstar would do well to understand that private spaces such as trade union Discord servers have protections, and that their company’s contractual clauses do not supersede UK law.” Marshall added that the union will “not be intimidated.”

Rockstar claimed that it fired the more than 30 workers in question for “gross misconduct, and for no other reason” and it accused them of “distributing and discussing confidential information in a public forum.” Engadget has asked the company, which last week delayed GTA VI by a further six months, to comment on IWGB issuing legal claims against it.

People Make Games reported this week that a collective of workers called the Rockstar Games Workers’ Union had recruited just over 10 percent of the company’s UK workforce to join. That’s one of the benchmarks needed to apply for statutory recognition in the country. If that were granted, the government would be able to force Rockstar to recognize the union. The Rockstar Games Workers’ Union was said to be just weeks away from formally announcing its existence before Rockstar allegedly fired a majority of the organizing committee.