The Competition and Markets Authority (CMA) said the pair have been running a duopolistic control off the mobile market via iOS and Android; their app stores; browsers and services bundled with mobile devices running their OSes.

The news could mean that third-party developers could actually get an ally on their side. Publishing the first part of a wide-ranging mobile ecosystem market study -- which was announced this summer -- today that it has "provisionally" found Apple and Google have been able to leverage their market power to create "largely self-contained ecosystems".

It said that the degree of lock-in damages competition by making it "extremely difficult for any other firm to enter and compete meaningfully with a new system".

"The CMA is concerned that this is leading to less competition and meaningful choice for customers", the watchdog writes in a press release.

"People also appear to be missing out on the full benefit of innovative new products and services -- such as so-called 'web apps' and new ways to play games through cloud services on iOS devices."