Microsoft began the new year arguing that government regulators need to crack down on Google to preserve fair competition in the Internet and smartphone markets.
The latest refrain came on Wednesday in a blog post by Dave Heiner, Microsoft's deputy general counsel.
His attack amounted to a last-ditch appeal to the US Federal Trade Commission and the European Commission as they wrap up wide-ranging investigations into Google's business practices. Resolutions to those probes are expected early this year, perhaps within the next week at the FTC.
Microsoft fears Google, perhaps its biggest nemesis, will emerge from the anti-trust probes without being required to make significant changes.
"Hopefully, Google will wake up to a New Year with a resolution to change its ways and start to conform with the antitrust laws," Heiner wrote. "If not, then 2013 hopefully will be the year when antitrust enforcers display the resolve that Google continues to lack."
For the past two years, Microsoft has been among the companies marshaling a campaign aimed at persuading regulators to force Google to changes its ways.
Among other things, regulators have been looking into allegations that Google has been highlighting its own services in its influential search results while burying links to competing sites.
The investigations also have delved into the way prices are set in Google's digital advertising system, the Internet's biggest marketing vehicle, and examined whether Google has been refusing to license key patents to mobile devices vying against gadgets powered by Google's free Android software.
Heiner mostly rehashed complaints that cast Google as a conniving company that abuses its dominance of Internet search, as well as its leadership in online video and smartphones, to thwart its rivals to the detriment of consumers.
Google Inc has steadfastly maintained that it hasn't done anything wrong while trying to give people better access to the information and other services they want.
In an attempt to make his case, Heiner focused on previously aired allegations that Google has cut off Microsoft Corp from the data it needs to improve the YouTube viewing experience of Windows smartphones users.
YouTube, which is owned by Google, hasn't designed a Windows Phone application for its popular video service. Microsoft views the snub as a calculated attempt to lessen the appeal of Windows Phones as they try to challenge Apple Inc's pioneering iPhone and the wide array of smartphones relying on Android. The YouTube apps designed for the iPhone and Android phones have become staples on those devices.
As a counter-measure, Microsoft has been trying to build its own YouTube app for Windows Phones for the past two years, only to be blocked by Google's refusal to license vital coding information, according to Heiner. YouTube's own leadership wants to cooperate with Microsoft, Heiner wrote, but those executives were overruled last month by their bosses at Google.
"Google's refusal deprives consumers who use competing platforms of a comparable experience in accessing content that is generally available on the Web, almost all of which is created by users rather than by Google itself," Heiner lamented.
In a statement, Google denied Microsoft's claims and stressed that all of YouTube's features are available through mobile Web browsers. "We've worked with Microsoft for several years to help build a great YouTube experience on Windows phones," Google maintained.