State regulators have given their support to a proposed 22-story luxury condo tower at 150 Seaport Blvd. that’s being challenged in court by environmentalists seeking more public access to the Boston waterfront.

The state Department of Environmental Protection said it will back developer Cronin Group’s application for a waterways license, a crucial permit needed to build the 263,000-square-foot tower at the Whiskey Priest and former Atlantic Beer Garden restaurant property.

The Boston-based Conservation Law Foundation challenged the $260 million project in court, arguing that the project violates state law that limits development on the waterfront.

That lawsuit remains active, with a Jan. 23 hearing scheduled in Suffolk Superior Court to hear oral arguments.

The DEP’s ruling was issued in a letter today by Ben Lynch, the head of the DEP’s waterways regulation program. Lynch wrote that DEP plans to approve the project because it meets requirements for public accommodations, including an 8,416-square-foot second-floor restaurant.

CLF Senior Counsel Peter Shelley said the plans for public space are “grossly inadequate” and the group will appeal the DEP decision.

“As bad as this approval is, all subsequent approvals have to be consistent with this one,” Shelley said. “So this really opens the doors to massive loss of public access around the commonwealth.”

The ruling could have implications for Chiofaro Co.’s plans for a 600-foot-tall tower at the Harbor Garage property and proposed redevelopment of the James Hook & Co. lobster pound property on Atlantic Avenue with a residential tower, Shelley said.

In a statement issued later Friday, Cronin Group said the DEP confirmed the benefits of the project, including the creation of a new 16,000-square-foot section of the Boston HarborWalk.

“Eliminating the current barrier to the water is one of the reasons that more than 2,100 community and business groups, individuals, and elected officials support this project while only one group opposes it,” the company said.