LONDON — Apple complained that requests from Meta Platforms for access to its operating software threaten user privacy, in a spat fueled by the European Union’s intensifying efforts to get the iPhone maker to open up to products from tech rivals.

The 27-nation EU’s executive Commission is drawing up “interoperability” guidelines for Apple under its new digital competition rulebook. The interoperability measures would ensure that devices like smartwatches or features like wireless file transfers work as smoothly with iPhones as do Apple Watches or AirDrop.

The EU’s rulebook, known as the Digital Markets Act, aims to promote fair competition in digital markets and prevent Big Tech “gatekeeper” companies from cornering markets. The commission posted proposed measures late Wednesday on how Apple should make its iOS operating system work with other technology.

In response, Apple said it’s “concerned that some companies — with data practices that do not meet the high standards of data protection law held by the EU and supported by Apple — may attempt to abuse the DMA’s interoperability provisions to access sensitive user data.”

The company singled out Meta, saying it has made at least 15 requests “for potentially far-reaching access to Apple’s technology stack” that would reduce privacy protections for users.

If those requests were granted, “Facebook, Instagram, and WhatsApp could enable Meta to read on a user’s device all of their messages and emails, see every phone call they make or receive, track every app that they use, scan all of their photos, look at their files and calendar events, log all of their passwords,” the company said in a report.

Meta, which owns Facebook and Instagram, fought back.

“Here’s what Apple is actually saying: they don’t believe in interoperability,” Meta spokesman Andy Stone said in a post on X. “In fact, every time Apple is called out for anticompetitive behavior, they defend themselves on privacy grounds that have no basis in reality.”

The Brussels-based European Commission’s proposed measures call for an approach based on Apple’s existing “request-based process,” in which developers ask for access to features and functions.

Apple should provide a “dedicated contact” to handle requests and give updates and feedback, and there should be a “fair and impartial conciliation” process to settle disagreements on technical issues.

The commission is now asking for feedback from the public by Jan. 9 on the proposals, including from any companies that have made interoperability requests from Apple, or are thinking of doing so.