A zoning debate in Manhattan's Sutton Place may seem like just another posh neighborhood telling a developer its project is not welcome.

But City Hall is listening for a bellwether in the bickering.

A zoning proposal put forward by residents of the neighborhood may force Mayor Bill de Blasio to finally have to reckon with a much-criticized affordable housing program he pledged to examine 15 months ago, experts said.

Near the beginning of 2017, Gamma Real Estate filed plans for a co-op on Sutton Place. Some nearby residents said the project, which is now slated to be nearly 800 feet high, would tower over the neighborhood and change its character.