The city’s heavily criticized rollout of its tax on luxury second homes is now the subject of a lawsuit by angry homeowners.

Their lawyer is a high-profile critic of Mayor Zohran Mamdani: former First Deputy Mayor Randy Mastro.

“It tried to flip the burden onto thousands and thousands of homeowners who are New York City residents, who should never have to be put through the burden and expense of having to apply for some exemption because the city didn’t do its job,” said Mastro in an interview with NY1.

That new suit is challenging Mamdani’s rollout of the new pied-à-terre tax that’s aimed at out-of-town homeowners whose properties are worth more than $5 million.

“A botched rollout that didn’t involve any of the work the Mamdani administration should’ve done before sending out any of those letters,” added Mastro, admitting he also got a letter from the city about his Manhattan home.

“I got one and everyone knows I’m a New Yorker and I’ve lived in New York City for a long, long time,” he said, saying that he was subject to a strict five borough residency requirement in order to be first deputy mayor for former Mayor Eric Adams — a job he held until the end of 2025.

The suit, filed on Staten Island, alleges the city “arbitrarily and capriciously foisted onto New York City residents the burden of proving they are not subject to the surcharge.”

The suit also claims the city was out of line for publishing a master list of owner names and property addresses that could be subject to the tax, as well as 17,000 letters issued to homeowners off of that list.

Two plaintiffs are related to Republican Council Member Frank Morano — who he says are not only city residents, but they also don’t own properties worth at least $5 million.

“My wife’s home, where we live and raise our family, appeared on the city’s public list, even though it is unquestionably our primary residence, and her name is on there. My name’s not on there, even though I’m just as much of an owner as she is,” said Morano in an interview with NY1.

“My dad’s home, which he’s lived in for 30 years, also appeared on the list. Neither one of us received one of these 17,000 letters, but that alone tells you how confusing and over broad the rollout was,” he added.

“It looks like speed and politics took precedence over precision. The administration wanted to get a signature tax the rich initiative up and running quickly, and instead of first using all the information available to government to narrow the universe of people who might actually owe the tax, they cast a very wide net and put the burden on homeowners to sort it out afterward,” Morano said.

Mastro says he wants the city’s notices deemed null and void.

“And that the city has to do it over and actually do its homework and make an initial determination whether a property is actually subject to the tax,” he told NY1.

The Law Department will defend the city in the lawsuit, according to a Mamdani spokesperson.

“The pied-a-terre surcharge will help deliver the city New Yorkers deserve: cleaner parks, safer streets, and critical public investments that make our city a more affordable place,” said Matt Rauschenbach, a City Hall spokesperson.

The city says about 2,600 New Yorkers have filed for exemptions from the tax after they got letters telling them they might be on the hook for a bigger tax bill. Residents have until next month to appeal.

Marvin Ciperon submitted personal documents with the help of his local councilwoman.

“Whether that’s fling the exemption like we did for Marvin, or just have questions regarding what the letter may mean because we know that simply receiving the letter doesn’t mean that you will have to pay this tax,” said Democratic Council Member Shahana Hanif.

“This will be successful, and I will also be working very closely with the mayor to ensure that that’s exactly what happens,” she added.

He’s attempting to prove he’s been a city resident since the 1970s — and fending off an estimated $41,000 property tax increase.

Ciperon’s exemption was filed in less than 20 minutes. He also got a call from a Mastro associate to join the lawsuit, but declined.

“We and lots of people in this neighborhood of our generation made a decision to invest in the city, in the city’s future, with our lives and our children,” said Ciperon.

“We were attracted to moving here, so that shouldn’t be held against us in the future, because the neighborhood has gone from a place where no one wanted to live, or led money to a place where we could never afford to move to,” he continued.

The City Council is holding a hearing on the tax rollout on Aug. 18.