Three New Yorkers are suing Mayor Zohran Mamdani over his recently implemented tax on luxury second homes, accusing the mayor’s office of causing chaos and wrongly suggesting thousands of people might owe taxes on homes that don’t actually qualify.

The suit does not challenge the underlying tax law. Instead, it accuses the Mamdani administration of failing to follow state notice requirements and setting off a “panic” in late July by releasing a list of nearly 1 million properties that might be hit with pied-à-terre surcharge, then mailing about 17,000 notices to a smaller group of property owners.

The state court action seeks to have those notices declared “null and void.”

“The mayor wanted a headline, and he got one,” attorney Randy Mastro, a former top aide to Eric Adams and Rudy Giuliani who is representing the group, told Gothamist. “Thousands of people who owe nothing have been confused, exposed, and put to real expense so this administration could make a political point. That is not lawful notice.”

The Independent has contacted the mayor’s office and New York City departments of law and finance for comment.

The lawsuit has ties to Mamdani’s political rivals.

One of the plaintiffs is Rachel O’Brien, who is married to Republican City Councilmember Frank Morano, whose father is another plaintiff. Mastro, meanwhile, served as first deputy mayor under Adams and as Giuliani’s chief of staff.

The city has defended its approach to the tax, which applies to homes worth more than $5 million and co-ops and condos worth more than $1 million that are not used as primary residences.

It argues it was bound under state law to release the list of properties, and it has since given homeowners an extension of until September 18 to apply for an exemption.

New York will “vigorously defend the city against this suit” Mamdani spokesperson Matt Rauschenbach told The New York Times.

The pied-à-terre tax, passed in May, will bring in an estimated $500 million annually. The mayor argues the tax is necessary to strengthen the city’s budget and expand social services.

Mamdani has pitched the tax as only impacting the “richest of the rich,” whose buildings are “sitting empty” while their owners are “able to reap the huge financial rewards“ of holding property in New York City.

“This is a fundamentally unfair system that hurts working New Yorkers,” Mamdani, who ran on taxing the rich, said in April. “Now, it’s coming to an end.”

The tax has faced criticism from wealthy New Yorkers since the beginning, though some experts argue that their claims the tax will set off capital flight are overblown.

“I don’t think a lot of the typical concerns about migration are concerns when it comes to the pied-à-terre tax,” Emily Eisner, executive director and chief economist at the left-leaning Fiscal Policy Institute, told The Guardian. “I’m not concerned about dampening real estate markets.”

Mamdani angered figures across the business world in April by standing outside of Wall Street billionaire Ken Griffin’s luxury building to promote the tax.

In the fallout, Griffin and his hedge fund threatened to pull out of planned skyscraper project, though the development is still moving forward with Griffin’s Citadel as an anchor tenant.

Mamdani’s pied-à-terre tax is part of a larger wave of populist policies bubbling up from the Democratic party’s left flank.

In California, a proposal for a one-time tax on billionaires to make up for Trump administration health funding cuts has angered the state’s vaunted tech industry and divided Democrats in the state.