Microsoft and Google are still fighting about the Windows Phone YouTube app. This has been going on for months, with no apparent resolution on the way.

Back in May, Google sent Microsoft a cease and desist letter for building a native YouTube app, claiming that it violated its terms of service in three areas. It allowed users to download videos, it prevented the display of ads in YouTube video playbacks and it played videos that Google’s partners had restricted from playback on certain platforms (like mobile devices).

“These features directly harm our content creators and clearly violate our Terms of Service,” Google said.

Since then, the two companies have actually been working together to deliver a suitable app that would both please Windows Phone users (and Microsoft) and meet Google’s conditions. Microsoft thought they had reached that point. Earlier this week, it released its new YouTube app, after addressing the aforementioned issues. Then, Google blocked it.

The Verge quotes a Microsoft spokesperson before the app was blocked:

We’ve released an updated YouTube app for Windows Phone that provides the great experience our consumers expect while addressing the concerns Google expressed in May, including the addition of ads,” says a spokesperson. Microsoft says it appreciates “Google’s support in ensuring that Windows Phones customers have a quality YouTube experience and look forward to continuing the collaboration.”

Then it quotes a Google spokesperson, and again a Microsoft spokesperson after the app was blocked:

“Microsoft has not made the browser upgrades necessary to enable a fully-featured YouTube experience, and has instead re-released a YouTube app that violates our Terms of Service,” says a Google spokesperson. “It has been disabled. We value our broad developer community and therefore ask everyone to adhere to the same guidelines.”

..

Microsoft says it’s working on resolving the issue with its updated YouTube app. “Google is blocking our updated YouTube app for Windows Phone,” says a Microsoft spokesperson. “We are working with them to resolve the issue.”

Now, Microsoft’s Corporate Vice President & Deputy General Counsel, Litigation & Antitrust, has put out a scathing blog post about Google, suggesting that Google is just making excuses for blocking the app because it doesn’t want it on devices that don’t use Google as the default search provider like Android and the iPhone.

He writes, “Google’s objections to our app are not only inconsistent with Google’s own commitment of openness, but also involve requirements for a Windows Phone app that it doesn’t impose on its own platform or Apple’s (both of which use Google as the default search engine, of course).”

He later writes:

Google asked us to transition our app to a new coding language – HTML5. This was an odd request since neither YouTube’s iPhone app nor its Android app are built on HTML5. Nevertheless, we dedicated significant engineering resources to examine the possibility. At the end of the day, experts from both companies recognized that building a YouTube app based on HTML5 would be technically difficult and time consuming, which is why we assume YouTube has not yet made the conversion for its iPhone and Android apps.

For this reason, we made a decision this week to publish our non-HTML5 app while committing to work with Google long-term on an app based on HTML5. We believe this approach delivers our customers a short term experience on par with the other platforms while putting us in the same position as Android and iOS in enabling an eventual transition to new technology. Google, however, has decided to block our mutual customers from accessing our new app.

It seems to us that Google’s reasons for blocking our app are manufactured so that we can’t give our users the same experience Android and iPhone users are getting. The roadblocks Google has set up are impossible to overcome, and they know it.

You can read the whole thing here.

As far as Microsoft is concerned, it has done everything Google wanted, Google is being unfair, and the ball is in Google’s court.

We have yet to see Google’s rebuttal to Microsoft’s post.