A month after losing a partial case in the Federal Court of Australia, Google is now grappling with an even bigger challenge in its long-running fight with Fortnite maker Epic Games.

Last month both Google and Apple were found to have breached section 46 of the Competition and Consumer Act by using their control of app distribution and in-app payment systems to substantially lessen competition.

Now Google has asked the US Supreme Court to intervene in its Epic Games battle, seeking to delay sweeping changes to its Android app store operations.

The move follows Google’s failed appeal last month, which left in place a permanent injunction requiring it to open the Google Play Store to rival marketplaces and alternative payment systems. Unless the Court acts by October 17, the ruling will take effect just three days later.

The injunction compels Google to allow third-party app stores to operate inside the Play Store, share its catalogue with competitors and permit developers to bypass its in-app billing system.

Google argues the changes will expose users to “enormous security and safety risks” by enabling malicious or pirated apps, while placing new burdens on developers to track how their apps appear across multiple platforms.

The company also claims the ruling undermines its ability to recover costs for Play Store services unrelated to payments.

Epic, which first sued Google in 2020, alleged the tech giant used its dominance to stifle competition in violation of US antitrust laws.

A jury sided with Epic in 2023, handing the gaming company a far bigger victory than it secured in its separate fight with Apple.

While the Supreme Court previously declined to take up Apple’s request in its own Epic case, some suggest Google’s wider obligations under the injunction could prompt a different response.

Google has said it will formally petition for a full review by October 27.

Alphabet shares dipped following the latest filing, with the company warning the ruling could affect more than 100 million Android users and half a million developers in the US alone.