A bipartisan coalition of Senators introduced legislation last Wednesday to "break the ironclad grip" of both Apple (AAPL  ) and Google (GOOGL  ) over their respective app stores.

The bipartisan bill was authored by Richard Blumenthal (D, CT) and Marsha Blackburn (R, TN) and was sponsored by Senate antitrust subcommittee chair Senator Amy Klobuchar (D, MN).

Called the Open App Markets Act, the legislation would require both Google and Apple to open their Android and iPhone ecosystems to third-party app stores, applications, and payment solutions, among other things.

"This legislation will tear down coercive anticompetitive walls in the app economy, giving consumers more choices and smaller startup tech companies a fighting chance," said Senator Blumenthal.

Senator Blumenthal told Reuters that he expects companion legislation out of the House of Representatives "very soon" in an interview on Wednesday.

No doubt the bill comes as welcome news to developers weary of sending as much as 30% of their profits to the likes of Apple and Google.

In return, the world's valuable company has a lot to lose should the new law reach the President's desk. Much of Apple's $53.8 billion in annual service revenue flows from the 15-30% cut it earns on in-app sales. Under the new law, users could sideload apps and use other payment systems, potentially shrinking Apple's service business significantly.

The App Store "is the cornerstone of our work to connect developers in a way that is safe and trustworthy. The result has been an unprecedented engine of economic growth and innovation," said Apple in a statement shortly after the legislation was announced.

Google didn't directly comment on the bill itself. Still, a spokeswoman pointed to previous statements from the search giant stating that Android phones offer more choices than others. Many Android phones come with third-party app stores pre-installed, and users can download and install apps from outside the official Play Store.

The Open App Markets Act would also enshrine the rights of developers to alert users to lower prices on software outside official App Stores. And Apple and Google are barred from using "non-public data" to inform the development of their own competing apps.

The law aims to address many of the concerns raised in an April Senate hearing. During which, Spotify (SPOT  ), Match Group (MTCH  ) , and others accused the tech giants of profiting unfairly from commissions earned through payment processing, among other things. According to the new law's sponsors, this testimony proved that Apple and Google stifle competition by acting as gatekeepers for the mobile app market.

Currently, a federal judge is reviewing testimony that could see Apple ceding some of the 30% its collects from digital sales regardless of whether the new law passes or not.

The plaintiff in that suit, Epic Games has also filed a suit against Google, concurrently with several state attorney generals. Epic and the AGs allege that Google illegally worked to monopolize app marketplaces on its Android phones.

"This [legislation] will make it easier for developers of all sizes to challenge these harmful practices and seek relief from retaliation, be it during litigation or simply because they dared speak up," said Epic Games VP of Public Policy Corie Wright to TechCrunch.