The fight over a new Seaport tower roars on despite unanimous approval Wednesday from the Boston Planning & Development Agency's zoning commission.

The 250-foot 150 Seaport Blvd. had its final city vote Wednesday, and many of the project’s supporters showed up to City Hall to voice their enthusiasm. The multifamily development’s distinct billowing sail architecture won the praise of Mayor Martin Walsh, who sent several surrogates to the meeting to express his opinion. South Boston neighbors and representatives from Catholic charity the Labouré Center spoke in favor of Jon Cronin, head of the building’s development team, and his commitment to providing affordable, single-unit housing for seniors.

The 292K SF development has sparked debate over whether it provides enough public access to the waterfront on its small lot. In November, Cronin Holdings added more public space and amenities to appeal to the state and environmental groups. 11K SF of ground-floor retail, an expanded Harborwalk, and upgrades to the adjacent Seaport Wharf water taxi and ferry terminal come with the project. The developer is also donating money to build Martin Richards Park in Fort Point.

“We worked hard to create public access where there isn’t,” Cronin said during his presentation to the zoning commission. “We scrapped the original design and created something the mayor would be proud of.”

Some groups are not convinced of the public benefits from the luxury residential tower. Cronin said the Conservation Law Foundation and Boston Harbor Now have been the most vocal opposition, but he said one was at least willing to negotiate. The CLF filed a lawsuit last month against the state and Cronin for restricting waterfront access after the state signed off on the project in December.

“The 150 Seaport project is primarily for private benefit and many of the public benefits being ‘offered’ at the site — such as the harbor walk, have been legally required there since 1997. That is why CLF has challenged it. Without a new tidelands license issued by the Commonwealth, the project cannot go forward,” CLF press secretary Josh Block said in a statement Wednesday to Bisnow.

Boston Harbor Now recognizes Cronin has received the blessing of the city and state, so it is focused on holding the developer to his words.

“Our interest is making sure the public interests are heard,” said Jill Horwood, director of waterfront policy at Boston Harbor Now. “They were given a 5K SF amplification by the state for Seaport Wharf — we want to make sure they take advantage and make the public facilities meaningful.”

With the state passing its new Municipal Harbor Plan last month, construction should start in the fall, representatives with Cronin said. The small wedge of a site will require a $10M extension of the Harborwalk built over the water due to size constraints, but the zoning commission indicated it was the best the developer could do given the complexity of the site.

“Boston’s waterfront is largely built out. It’s these small tricky spots that will lead the conversation going forward,” Horwood said.