Microsoft has backed “Fortnite” video game maker Epic Games in its legal battle with Apple – alleging in a new court filing that the Tim Cook-led tech giant has “stymied” its own efforts to create an Xbox mobile store.

Microsoft says Apple's App Store rules are to blame for the continued delay of the Xbox mobile app store it announced last summer. In an amicus brief filed this week first spotted by The Verge, Microsoft expressed support for Epic Games in the company's long-running bout against Apple.

Microsoft filed an amicus brief supporting Epic Games' fight against Apple over its control over the App Store.