But elected officials, developers and others say that for the first time in nearly half a century there is a consensus on what should happen. The plan has the support of Councilwoman Margaret S. Chin; State Senator Daniel L. Squadron; Community Board 3; and the State Assembly speaker, Sheldon Silver, who lives nearby and has blocked past proposals.

The redevelopment of the area had eluded Mayors John V. Lindsay, Edward I. Koch and Rudolph W. Giuliani, as well as Mr. Bloomberg in 2003. The longstanding split in the community had some Latinos and housing advocates demanding that the city build only low-income housing on the site, while residents of the nearby co-ops countered that only commercial development was appropriate.

“It was an exercise in frustration,” said Richard LeFrak, a developer who was twice selected to rebuild Seward Park but was unable to move forward. “You had the collision between the Jewish community in the Grant Houses and the Latino and Asian communities.”

The six blocks in the Seward Park urban renewal area have served as a symbol of the struggle to preserve affordable housing in working class neighborhoods against rapidly encroaching luxury development. Just north of Delancey and Essex Streets, the Blue Building, a 17-story glass condominium built in 2007, towers over the neighborhood.

During the recession, late in 2008, Dominic Berg, then the chairman of Community Board 3, convened a committee to try to reach a consensus. “People were tired of looking at empty lots,” Mr. Berg said.

At the same time, Madelyn Wils and David Quart, executive vice presidents at the city’s Economic Development Corporation, also began working on creating a ground-up development plan for the largest city-owned site below 96th Street. Her bosses were skeptical, but gave them the go-ahead.