Elon Musk has voiced concern over Nvidia’s upcoming Arm acquisition, joining a growing list of concerned parties.

Nvidia rocked the semiconductor market when it announced a deal to acquire Arm, the leading British tech company. Arm holds a unique position in the industry, creating and licensing chips designs that its customers then manufacture for their own use.

Skeptics immediately started voicing concern over a US-based company buying Arm, especially one that would have a vested interest in keeping Arm’s best innovations for itself. Should Nvidia go that route, it would be a major departure for Arm, which has always been the semiconductor version of Switzerland — remaining strictly neutral and selling to everyone and anyone. To date, no amount of reassurance on Nvidia’s part has assuaged those concerns, with UK lawmakers threatening to block the deal.

According to The Telegraph, via Reuters, Elon Musk has also expressed concern over the prospective merger. In addition, Amazon and Samsung have both come out in opposition to the deal, expressing such to US authorities.

Given the existing opposition from UK authorities, additional opposition from CEOs and other companies is sure to add additional pressure to what is already a tenuous deal.