Game Workers Unite announced they are preparing to take legal action against Ustwo Gamesthe developer behind Monument Valley and Assemble with Care, for allegedly firing a senior programmer for union activity in the workplace.

Austin Kelmore, a founding member of the UK branch of Game Workers Unite, had his employment with the company terminated, having previously received emails complaining of his union work from Ustwo’s HR department, according to the union. In a statement from Game Workers Unite, they claim Austin received emails criticizing him for spending time on “company feedback, diversity schemes and working practices.”

The email, which was apparently sent back in October, concludes with, “The studio runs as a collective ‘we’ rather than leadership v employees, which may have been Austin’s experience in the past, but it’s not how things are here.”

Ustwo Games deny these allegations, saying to GameLuster that: “Austin Kelmore is currently an employee of Ustwo Games and will be leaving in the near future for reasons unconnected to his membership of a trade union or his undertaking trade union activities.”

The company also stated that it “have other employees who are members of trade unions,” and it “will continue to be committed to diversity and inclusivity. [It works] hard to build a supportive work environment for all our employees.” They would not comment on why they dismissed Kelmore outside of this, citing privacy concerns.

Union secretary Jamie Cross commented on the alleged union busting.

“Despite Ustwo’s claims of being as much a family as it is a company, it has decided to leave Austin, one of its best developers, completely orphaned,” Jamie said. “Austin and his family are not only left without their main source of income, but also unsure if they will have to uproot their whole lives and leave the country in a few weeks.”

Cross explains that Kelmore, a U.S. national, now has his immigration status at risk, as he came to the U.K. under a general work visa with Ustwo. Game Workers Unite say they will “not stand idly by in the face of this unlawful and vicious act, and is determined to fight back until this decision is reversed, either voluntarily or through the courts.”

The union have given Ustwo until Friday to reverse this decision before they launch legal proceedings. If it is found that Austin’s dismissal is a result of his union work, this may breach section 152 of the Trade Union and Labour Relations (Consolidation) Act 1992. Section 152 states that a dismissal is unfair if the primary reason for it includes “had taken part, or proposed to take part, in the activities of an independent trade union.”