In a significant setback for Mayor Bill de Blasio's affordable housing plan, the City Council on Tuesday rejected a proposed Upper Manhattan residential development that would have used new zoning regulations. NY1 Political Reporter Courtney Gross has more on the defeat of the project known as Sherman Plaza.

The promise to turn this Inwood building into affordable housing has quickly evaporated.

"Unfortunately we couldn't reach an agreement with everything that we had on the table," said City Councilman Ydanis Rodriguez, whose district includes the proposed development.

On Tuesday,  the City Council rejected a plan to build 355 apartments here — a decision that resonated well beyond the neighborhood and City Hall. That is because the developer was the first to try to use new zoning regulations under the mayor's affordable housing plan.

The regulations, called mandatory inclusionary housing, allow developers to build larger if the project includes affordable housing.

And it was the size of the building that sparked community outrage and fear of gentrification.

Protests persuaded the local Councilman to vote no. The rest of the Council followed their colleague's lead.

Prior to Tuesday's vote, Ydanis Rodriguez had said he wanted half the development to be affordable housing. According to city officials, that deal was reached and a draft agreement was circulated.

He would not tell NY1 why he changed his mind.

"I am not going to be getting into details," the Councilman said. "All I am going to say is we could not reach an agreement."

The developer released a statement on Tuesday saying in part: "The project was an opportunity to develop 175 affordable apartments and we are disappointed the local council member did not agree with us."

Meanwhile, the City Council speaker downplayed the implications of the decision.

"Again, I don't see it being in any sort of way an indication of where we are heading with MIH," said Council Speaker Melissa Mark-Viverito. "I believe this is a very rare situation."

The question is could Sherman Plaza be some sort of standard bearer here at the City Council. We already know of one similar project in the pipeline that could be rejected.

The council majority leader has a 200-unit affordable housing development in his Queens district up for approval next month.

He plans to reject it too.

"We can't have a cookie cutter approach where anything goes as long as it meets the mayor's standards," said Queens Councilman Jimmy Van Bramer. "It has to meet community standards."