In January, Microsoft revealed plans to acquire the industry giant Activision Blizzard in a shocking $68.7 billion deal.

There were worries at the time about the impact this would have on ongoing investigations into sexual harassment and abuse at Activision Blizzard. But things got a lot more serious this week when four U.S. senators signed a letter of concern to the FTC over the deal. They argue that if the acquisition results in worse outcomes for the negotiating position of Activision Blizzard’s striking workers, the FTC should oppose the merger going forward.

Sens. Bernie Sanders, Elizabeth Warren, Sheldon Whitehouse, and Cory Booker were the four signatures, requesting the FTC investigate the deal’s legitimacy. The letter goes into detail about the “frat boy culture” at Activision Blizzard that government investigations uncovered, where perpetrators of sexual misconduct and discrimination were allegedly protected by the company and its CEO, Bobby Kotick.

Calls by Activision Blizzard workers for Kotick to resign because of this were also highlighted. Microsoft’s acquisition has resulted in Kotick remaining as CEO until at least 2023, guaranteeing him millions in profit and a potential “golden parachute” if he doesn’t leave voluntarily. The senators call this result “unacceptable” with such public demand for Kotick’s removal.

The letter also accuses Microsoft’s opportunistic acquisition efforts of potentially harming the efforts of Activision Blizzard employees attempting to unionize. QA workers at developer Raven Software began requesting for voluntary recognition of a formed union after weeks on strike in January. This followed 12 team members being denied new contracts last December.

While Microsoft has said that it will respect the outcome of the union drive currently underway in the company, the senators describe it as lip service that “provides no assurances of Microsoft’s promise” and said it “leaves multiple ways for Microsoft to undermine the unionization process and its outcome.” They pointed to one example in 2014, where Microsoft QA workers unionized and were then dismissed two years later.

“We are deeply concerned about consolidation in the tech industry and its impact on workers, and this proposed merger has already hurt workers at Activision Blizzard in their fight for a stable job and safe working environment”, the letter concludes. They ask the FTC to consider the history of both companies and the merger itself when assessing the anticompetitive effects of the deal.

While the U.S. government investigates Microsoft’s acquisition of the publisher, more lawsuits continue to hit Activision Blizzard as further allegations of sexual harassment and discrimination surface.