Microsoft originally voiced its concerns over a lack of a full Windows Phone YouTube app nearly two years ago, but the software giant has decided to resurface its complaint as 2013 gets underway. Microsoft's Dave Heiner posted a fresh blog post on the company's legal blog today to highlight his concerns over Google's behavior. "Google continues to prevent Microsoft from offering consumers a fully featured YouTube app for the Windows Phone," claims Heiner.

Central to Microsoft's complaint is a lack of official YouTube APIs for third-parties to use for access to YouTube's metadata and video playback. One particular YouTube Windows Phone app, MetroTube, faces issues when Google alters its backend code for YouTube — breaking video playback. MetroTube uses workarounds to access the required data on Windows Phone.

Google dropped a Gmail-shaped bomb on Windows Phone recently

Google recently dropped a Gmail-shaped bomb on Windows Phone by announcing its plans to drop Exchange ActiveSync protocol support for its free Gmail accounts from January 30th. Existing devices will be left unaffected with push email, contacts, and calendar in place, but Microsoft needs to put a fix in place before the months end to address the functionality. Google is moving to CalDAV and CardDAV support for Gmail, protocols that Microsoft does not currently support in Windows Phone.

Microsoft's latest YouTube complaint is the latest in a long line of issues between Redmond and Google. An antitrust complaint from Microsoft against Google in Europe appears to have soured relationships between the firms and Microsoft's recent ant-Google "Scroogled" campaign, "Bing it on," and Gmail man have clearly increased tensions. Google recently revealed it has "no plans to build out Windows apps" beyond a search app for Windows 8 and Windows Phone.