Microsoft has admitted that Windows Phone 8 doesn't work as well with some of the internet's most popular properties as do other smartphone platforms, but it has pinned the blame on a surprising culprit: apparently, it's all Google's fault.

In a blog post on Wednesday, Microsoft VP and deputy general counsel Dave Heiner said the software giant has spent two years trying to get a first-class YouTube app running on Windows Phone, but to no avail, thanks to the Chocolate Factory's stonewalling.

"YouTube apps on the Android and Apple platforms were two of the most downloaded mobile applications in 2012, according to recent news reports," Heiner wrote. "Yet Google still refuses to allow Windows Phone users to have the same access to YouTube that Android and Apple customers enjoy."

According to Heiner, Google has denied Microsoft's YouTube app access to metadata that would allow it to deliver all of YouTube's functionality, including such features as user ratings and the ability to search for videos by categories.

Because of this limitation, he says, Microsoft has been forced to deliver an app that's really nothing more than a repackaged version of the YouTube website running in a browser – unlike the apps for other platforms, which offer richer experiences.

Although YouTube execs have seemed amenable to helping Redmond get its YouTube app up to par with the others, Heiner says those efforts have been blocked from higher up the Chocolate Factory's food chain.

"Just last month we learned from YouTube that senior executives at Google told them not to enable a first-class YouTube experience on Windows Phones," he wrote.

If that accusation proves to be true, it would be a serious matter. Google spent much of 2012 under the scrutiny of competition watchdogs on both sides of the Atlantic, over complaints from Microsoft and others that the search giant's business practices were designed to edge its rivals out of the market.

This isn't the first time Microsoft has complained that Google's actions impaired how Windows Phone devices work with Google services. Last month, the company said it was "very surprised" to see Google discontinue its free Google Sync service, which allowed Gmail users to sync their mail, calendars, and contacts with Windows Phone devices via the Exchange ActiveSync protocol.

Google explained that users would still be able to sync their data using open-standards protocols including CalDAV, CardDAV, and IMAP. But Microsoft argued that these were "older protocols," and that using them would force Windows Phone owners to "degrade their mobile email experience."

For its part, Microsoft – an underdog in the mobile space – has urged users of competing smartphone platforms to switch their free email to Microsoft's Outlook.com service, which the company says is superior, "especially on your phone or tablet."

In the nearer term, however, Microsoft's complaints seem designed to urge regulators to increase their scrutiny into Google's business practices, at a time when US and EU watchdog agencies seem close to striking compromise agreements with the company. As Heiner writes:

Google dismisses these concerns as little more than sour grapes by one of its competitors. But the reality is that consumers and competitors alike are getting "scroogled" across the Web on a daily basis from this type of misconduct. Hopefully, Google will wake up to a New Year with a resolution to change its ways and start to conform with the antitrust laws. If not, then 2013 hopefully will be the year when antitrust enforcers display the resolve that Google continues to lack.

Google did not immediately respond to The Reg's request for comment on the matter. ®