(Pocket-lint) - There is a new twist in the battle between Apple and Fortnite publisher Epic Games, and it might impact countless apps and games that leverage Epic's Unreal Engine. Basically, Epic says Apple has threatened to cut off its access to all iOS and Mac developer tools.

Epic recently rolled out a new update that broke Apple and Google's rules on in-app purchases. Basically, the new update made it so Epic could directly collect revenue from purchases of V-bucks, Fortnite's in-game currency, effectively bypassing Apple and Google and cutting them both off from the 30 per cent cut they usually demand from developers.

Apple and Google responded by removing Fortnite from the App Store and Play Store. Epic promptly filed a civil lawsuit, released a video mocking Apple, and published a FAQ page detailing the ways it believes Apple and Google are abusing their dominance in the marketplace.

Now, Epic says Apple is retaliating, by threatening to boot Epic from the Apple Developer Program, which is required to use Apple's developer tools and to distribute apps on iOS devices. As part of this, Epic won't even be able to notarise Mac apps. All apps must be notarised before they can run the latest version of macOS, even if they’re not available via the App Store.

Also, without access to Apple's developer program and its developer tools, Epic told The Washington Post's Gene Park that all future Unreal Engine versions can no longer be developed or even updated for iOS and Mac devices (not including Windows), affecting not only Fornite but also an untold number of developers and studios who use Epic's software for their games.

These developers might need to scramble to develop new games or updates should Apple ultimately block their access to Unreal Engine. Apple is saying it wants Epic to “cure your breaches” within two weeks, according to a letter from the company that Epic shared, which isn't a lot of time.

Epic has already filed for a preliminary injunction against the company, claiming it will be irreparably harmed.

“Apple’s actions will irreparably damage Epic’s reputation among Fortnite users and be catastrophic for the future of the separate Unreal Engine business", Epic writes. “The cascading effect of losing ongoing Unreal Engine compatibility will threaten the viability of the engine and disrupt development of a constellation of apps and uses that rely on its graphics to render hundreds of video games".

Epic is also asking the court for Fortnite to be returned to the App Store. Meanwhile, Apple is giving Epic until 28 August to make its changes.

Writing by Maggie Tillman.