The Jets’ claim of $900 million in new tax revenues over 30 years from the proposed West Side stadium “is at best disingenuous,” an independent city agency contends.

In a terse March 17 letter to the football team’s president, L. Jay Cross, the Independent Budget Office slammed the Jets for making the claim in a recent commercial and attaching the figure to the IBO. The agency says its calculations put the figure at only $210 million over 30 years.

The 30-second spot says the IBO estimates “hundreds of millions of dollars in new tax revenue,” and then asks, “What could $900 million in new budget revenue pay for over 30 years?”