A Manhattan judge crushed a ban on Styrofoam and related products supported by Mayors Michael Bloomberg and Bill de Blasio — saying there’s plenty of evidence that recycling the materials could save the city at least $400,000 annually.

Justice Margaret Chan overturned the ban that went into effect on July 1, though penalties were delayed until 2016.

A coalition of business owners sued the city this year, saying the ban was only instituted for political reasons.

Chan ordered the Department of Sanitation to make a plan for how best to recycle polystyrene foam products.

She noted that Commissioner of Sanitation Kathryn Garcia calculated that the city would save $400,000 a year if 40 percent less Styrofoam went into landfills.

Yet Garcia said that recycling the material “would not be environmentally efficient [or] economically feasible.”

Chan said the business owners proved the opposite is true.

“The commissioner’s concern is not justified given the abundant evidence showing a viable and growing market for not just clean expanded polystyrene foam but post consumer material,” she said.

The products currently constitute only 0.8 percent of curbside waste and 28,500 tons in landfills.

“We disagree with the ruling,” said City Hall deputy press secretary Ishanee Parikh. “These products cause real environmental harm and we need to be able to prevent nearly 30,000 tons of expanded polystyrene waste from entering our landfills, streets, and waterways. We are reviewing our options to keep the ban in effect.”