Even as construction workers dig the foundation for a controversial trolley garage in Miami’s predominantly black West Grove to make way for a tony new development in Coral Gables, opponents are scrambling to stop it.

The question is, is it too late?

For Miami City Commissioner Marc Sarnoff, who met with neighborhood groups to seek support for the project, the answer is yes.

“This decision was not made in a vacuum,” Sarnoff said this week, explaining that the city’s Miami 21 zoning code gives the developer the right to build the garage. “This developer could build this facility there.”

But to West Grove residents, who unleashed a flurry of emails roundly criticizing Sarnoff for not making negotiations more public, the fight is far from over.

Last week, they started an online petition at change.org, and at 11 a.m. Saturday they will hold a rally at the site of the garage, in the 3300 block of Douglas Road. Neighborhood ministers will address the matter at an 8 a.m. meeting Saturday, and on Jan. 17, the Coconut Grove Village Council will take up the matter.

In addition, the University of Miami law school’s Center for Ethics and Public Service is researching whether city officials correctly applied zoning laws when it approved the garage in May without a public hearing. And the center is trying to find an attorney to take the case pro bono, said director Anthony Alfieri. The center’s new environmental justice clinic is also studying the impact the 12-bay garage will have on the health and safety of the residential neighborhood. The clinic’s Zach Lipshultz will present preliminary findings at the meeting of the pastors’ group.

“We just got to keep fighting,” said Pierre Sands, president of the Coconut Grove Village West Homeowner’s and Tenants Association, which has been representing residents in the area since the 1950s. “We’re just little folks on the outside looking in, trying to figure out what the heck is going on.”

The mounting criticism has put Sarnoff, whose district includes Coconut Grove, on the defensive. This week he insisted residents supported the project, even if they now say they oppose it.

“Did we take a photograph of them raising their hands? I didn’t. Was there outward approval? I would say 90 percent,” he said.

But residents say they never signed off on the deal, which started last March when Astor Development approached Coral Gables about swapping land on Le Jeune Road where the Gables operates a maintenance garage for its popular trolleys. Astor wants to build a seven-story, mixed use retail, office and apartment building, where luxury units will come with Sub Zero refrigerators and a concierge.

But first, Astor must build the garage. Astor explored buying land in Coral Gables, but it was too expensive. Then it found the land on Douglas Road.

This week, through a public relations firm, Astor issued a statement saying it had worked to make the garage compatible with the surrounding neighborhood. “The new facility will replace a property that was for the most part inactive,” it said.

Until Astor demolished the buildings in December, the block between Oak and Frow avenues held two houses, a rooming house and a popular restaurant. The site is surrounded by single-family homes.