Activision Blizzard has been given permission to intervene in Microsoft’s appeal against the UK’s Competition and Markets Authority’s decision to block its $102 billion deal.

This means Activision will be able to make their case to the tribunal alongside Microsoft’s own appeal.

The CMA “made fundamental errors in its calculation and assessment of market share data for cloud gaming services by failing to take account of constraints from native gaming (whereby gamers access games installed on their devices through a digital download or physical disc)”, according to Microsoft’s appeal, which has laid out five separate causes for appeal.

Credit: Call of Duty

Rima Alaily, Microsoft Corporate Vice President and Deputy General Counsel, said the CMA’s decision was “flawed for multiple reasons, including its overestimation of the role of cloud streaming in the gaming market and our position in it, as well as its unwillingness to consider solutions that received overwhelming industry and public support”.

“We are confident in the strength of our appeal and the binding commitments we have made to increase competition and choice for players today and in the future.”

Even if the companies are able to unwind CMA’s decision, more trouble comes from the Federal Trade Commission, who sued Microsoft in federal court overnight, seeking a court order blocking the takeover from going through before the deal’s July 18 deadline.

Microsoft sees this battle as the green light that may tip the decisions of other watchdogs around the world.

“We welcome the opportunity to present our case in federal court,” Microsoft President Brad Smith said in a statement.

“We believe accelerating the legal process in the U.S. will ultimately bring more choice and competition to the market.”