The UK’s Competiton and Markets Authority (CMA) has released Apple’s response to its Interim Report on mobile ecosystems. The Cupertino-based company has fiercely defended its ecosystem in the document, going so far as to say that it would need to “redesign the iPhone” to comply.

To bring you up to speed, the CMA’s Interim Report was initially released in December last year and last updated in January. It accused Apple and Google of having a “vice-like grip” on how people in the UK use their mobile phones. The companies were accused of running a duopoly that caused millions of users to “lose out.” At the time, the authority also suggested some guidelines for recourse.

Companies including Apple, Google, Microsoft, and Epic Games have filed responses to the Interim Report (IR). Apple’s 47-pager accused the CMA of basing its report on “unsubstantiated allegations and hypothetical concerns” voiced by the company’s rivals who could benefit from changes to Apple’s ecosystem. The iPhone maker added that the CMA cast aside apparent benefits of the iPhone’s tight-knit ecosystem, “ignoring them entirely or dismissing them on the basis of nothing more than speculation.”

Apple said it would need to redesign the iPhone so a handful of “powerful developers” could benefit.

“Apple is deeply concerned that the IR is proposing solutions to hypothetical problems that will result in real-world market interventions that could force it to redesign the iPhone to benefit a handful of powerful developers. The IR appears to assume that its proposed changes would be relatively simple. Yet many would require a complete re-architecting of a product that has existed for 15 years, has been constantly improved by Apple’s investment in IP, and is valued and trusted by millions of consumers.”

The company is referring to to the CMA’s suggestion that Apple gives users options for how they prefer to pay for IAPs, subscriptions, etc., instead of being tied to using proprietary billing systems. The company also addressed the market authority’s suggestion that Apple allows app sideloading. It said the CMA was “downplaying the security risks” of going that route. It stressed that several users choose Apple over Android because of its security. It said sideloading would “effectively remove the competitive differentiation between Apple and Android, taking this valued element of choice away from users.”

Apple also devoted several words to the CMA’s pointed disapproval of its WebKit restrictions that prevent rival browser engines from operating on its platforms. Apple said it proactively adds features to WebKit based on demand from users.

Apple spared no opportunity in its response to berate the CMA for relying on findings based on “untested” and “one-sided evidence.” It suggested that the market regulator analyze the benefits of Apple’s ecosystem for consumers and developers. It also urged that the authority ponder the “ramifications of any proposed intervention.”

Do you think Apple’s harsh response to the CMA was appropriate? Let us know in the comments. Further, if you have some time to spare, you can read the whole document here.