Apple and Google may be forced to allow third-party app stores onto their devices under a new Senate bill

• A bipartisan Senate bill threatens Apple and Google's app store domination.
• Under its terms, Apple and Google would need to allow users to access other app stores.
• The move is backed by Spotify and Fortnite developer Epic Games who have antitrust complaints against both tech giants.

Apple and Google's tight control over the mobile app ecosystems is under threat, as a bipartisan Senate bill threatens to force the pair to allow third-party stores on their devices.

Both companies have faced growing scrutiny over the way they run the App Store and Google Play store, respectively.

Apple takes a 15% to 30% cut from in-app purchases, a practice that developers have railed against, claiming it gives the company an unfair advantage.

Google, which takes a similar fee, has been accused of undermining alternative app stores on Android devices.

The new bill, the "Open App Markets Act", would apply to companies that operate an app store with 50 million or more US users.

Under its terms, Apple and Google would be forced to provide adequate space for alternative app stores and in-app payment mechanisms on their devices.

They would also be banned from using "non-public" information collected via their stores to create competing apps.

Developers would also have greater freedom in communicating with users about pricing and payment methods. Apple's developer guidelines currently that apps cannot "directly or indirectly target iOS users to use a purchasing method other than in-app purchase."

Introducing the bill on Thursday, Sen. Richard Blumenthal, a Democrat from Connecticut, said: "This legislation will tear down coercive anticompetitive walls in the app economy, giving consumers more choices and smaller startup tech companies a fighting chance."

Blumenthal unveiled the bipartisan bill alongside two Senate colleagues, fellow Democrat and one-time presidential hopeful Amy Klobuchar, and Sen. Marsha Blackburn.

The proposals come in the wake of the Senate antitrust subcommittee's hearing on app stores and competition, during which the likes of Spotify, Epic Games, and Protonmail called for an end to the tech giants' app store "monopoly."

The EU has accused Apple of breaching antitrust laws with its App Store after complaints from Spotify and Epic. The Fortnite maker also has an ongoing antitrust lawsuit in the US against Google.

An Apple spokesperson told TechCrunch: "Our focus is on maintaining an App Store where people can have confidence that every app must meet our rigorous guidelines and their privacy and security is protected."

In a statement issued on Thursday, Adam Kovacevich - a former Google lobbyist who now runs the Big Tech-backed industry group Chamber of Progress - said Congress had "better things to do than intervene in a multi-million-dollar dispute between businesses."

He added: "I don't see any consumers marching in Washington demanding that Congress make their smartphones dumber."

Insider approached Apple and Google for further comment.

Are you a current or former Googler with more to share? You can contact this reporter securely using the encrypted messaging app Signal (+447801985586) or email (mcoulter@businessinsider.com). Reach out using a nonwork device.