The UK competition regulator was refused permission to appeal a ruling which quashed a planned probe into Apple’s mobile browser and cloud gaming services, a further blow to the proposed investigation.

An appeal by the Competition and Markets Authority (CMA) of the Competition Appeal Tribunal (CAT) decision to block the probe was blocked by the latter.

It previously sided with Apple after it appealed the CMA decision to open a full investigation.

At the time, CAT explained the competition regulator had launched its investigation too late and so was not allowed to proceed.

The CMA aimed to open the probe after a year-long Mobile Ecosystem Market study found Apple and Google had an effective duopoly which allowed them to exercise a stranglehold over operating systems, app stores and web browsers.

Apple successfully appealed on its argument the investigation should have been opened in June, when the study was completed.

In rejecting CMA’s permission to appeal, CAT said the law on when the regulator could open a market investigation was clear.

“The letter of the law matters, even if it generates undesirable or unfortunate results,” it added.

At the time, the CMA said it was disappointed with the judgement and it will no doubt be further irked by the latest ruling.

It could now argue against the tribunal’s ruling directly to the UK Court of Appeal.

A representative told Reuters it is considering next steps.