Microsoft may face its biggest challenge yet to its acquisition of Activision Blizzard, with a report saying the FTC is likely to file a lawsuit to block the deal.

Microsoft announced a deal to purchase Activision for $68.7 billion in early 2022, one of the biggest tech acquisitions in history. The deal was met almost immediately with scrutiny, regulatory investigations, and challenges over concerns it would give Microsoft too much power in the gaming and PC market.

According to a report by Politico, the FTC is “likely” to challenge the deal in court over concerns it would give Microsoft an unfair advantage. Nothing has been decided for certain, but the outlet’s sources say FTC commissioners are skeptical of Microsoft and Activision’s arguments in favor of the deal.

As recently as September, CEO Satya Nadella was optimistic that the acquisition would win approval, but this latest development certainly casts doubt on that.

As Politico points out, it would be a major blow to Microsoft’s image if the FTC manages to scuttle the deal. Microsoft has worked hard to position itself as separate from Apple, Google, Meta, and Amazon’s antitrust issues, touting itself as a company that learned its lessons decades ago and has an enlightened approach to competition.