The European Commission, the bloc’s executive arm, announced official probes on Monday into whether Apple and Google owner Alphabet were unduly favouring their own app stores, as well as Facebook owner Meta’s use of personal data for advertising.

The probes fall under the Digital Markets Act, which is designed to tackle the dominance of so-called digital “gatekeepers” — the biggest online platforms — and came into effect earlier this month.

If found guilty of non-compliance, companies face hefty fines that could amount to up to 10 per cent of their global turnover...

The Commission said it was concerned that Apple and Alphabet had imposed “restrictions and limitations” that constrained developers’ ability to promote other services...

It also opened proceedings against Meta over whether the group’s new “pay or consent” subscription model complied with the DMA requirement for gatekeepers to obtain user agreement to “combine or cross-use their personal data”, such as for advertising purposes...

Tech companies pushed back on Monday against suggestions of wrongdoing. Apple said it was “confident” it was complying with the DMA, adding: “We’ll continue to constructively engage with the European Commission as they conduct their investigations.”

Amazon said it was “compliant” with the rules and that it had “engaged constructively with the European Commission on our plans since the designation of two of our services”.

Meta said: “Subscriptions as an alternative to advertising are a well-established business model across many industries . . . We will continue to engage constructively with the Commission.”

Oliver Bethell, director of competition at Google, said: “To comply with the Digital Markets Act, we have made significant changes to the way our services operate in Europe . . . We will continue to defend our approach in the coming months.”