One of Apple’s top software executives has hit out against Europe’s proposed Digital Markets Act, saying the provisions that allow third-party app stores into its ecosystem is “a step backwards.”

Craig Federighi, Apple’s senior vice president of software engineering, used the Web Summit conference in Lisbon yesterday to deliver his takedown of the proposed law.

“European policy makers have often been ahead of the curve, but requiring sideloading on iPhone would be a step backward,” he says.

“Instead of creating choice, it would open a Pandora’s Box of unreviewed, malware-ridden software and deny everyone the option of iPhone’s secure approach.”

Americans lawmakers ruled in September that Apple must allow app developers to point users towards outside payment systems, but didn’t order sideloading.