Mayor Bill de Blasio has set his sights on rezoning the Manhattan neighborhoods of SoHo and NoHo to allow for the development of what the city says could be thousands of new housing units.

De Blasio's plan would mark the first change to SoHo and NoHo’s zoning rules in more than 50 years. It would pave the way for 3,200 new units, with 800 permanently affordable.

“We have an opportunity here to create affordable housing — to bring to an area that has been upper income a greater mix of New Yorkers,” de Blasio said Wednesday at a daily news briefing, according to The New York Times.

The change would come under the Mandatory Inclusionary Housing program, which allows developers to build beyond zoning caps in some circumstances in exchange for creating affordable housing in their developments. The New York City Council approved the program two years into de Blasio's first term.

There was immediate backlash from some groups in the community to the proposed rezoning. SoHo Alliance leader Sean Sweeney told Crain’s New York Business he is worried about the lack of detail and concerned about skyscrapers being built in the area.

“I wish there was more information,” he said. “And I want real affordable housing. I want housing for the poor, not for the upper-middle class.”

Greenwich Village Society for Historic Preservation Executive Director Andrew Berman told the Times the “upzoning approach of super luxury towers” with limited affordability will be a negative for the area and the city as a whole.

Right now, the city is grappling with major unemployment and the effects of a years-long housing affordability crisis.

Rezoning attempts, which are often contentious, also often fail. Industry City's developers in late September officially dropped their application to rezone the Sunset Park project. Jamestown Properties, Belvedere Capital and Angelo Gordon & Co. wanted to rezone the site to allow for a $1B revamp that included office, hotel and retail space. Council Member Carlos Menchaca, who represents Sunset Park, opposed the application, saying it would drive people out of the neighborhood.

De Blasio's plan for rezoning in SoHo and NoHo would require several rounds of review and public hearings.