The city’s bid to toss an NYPD sergeant’s vaccine mandate lawsuit was shot down by a Manhattan judge — in what could be the first such ruling since Mayor Eric Adams lifted the COVID-era rule requiring Big Apple workers to get the jab.

Attorney James Mermigis – dubbed the “Anti-shutdown” lawyer for his pandemic-related litigation – told The Post that the city has sought to get roughly 50 of his cases tossed out as moot since the mandate was lifted on Feb. 9.

On Tuesday, in what could be a first-of-its-kind ruling, Manhattan Supreme Court Justice Erika Edwards rejected the city’s argument in one such lawsuit — filed by NYPD Sgt. Patrick Agugliaro after his request for a COVID-19 vaccine exemption on religious grounds was denied.

The judge agreed to overturn the city’s denial of Agugliaro’s request, finding it was “devoid of any explanation,” and shot down the argument that his suit was no longer relevant in her decision.

Unlike hundreds of city employees, Agugliaro wasn’t fired over his refusal to get the jab as his attorney, Mermigis, was able to obtain a temporary restraining order as his case played out in court.

Mermigis, who represents roughly 100 city workers in such lawsuits – the majority of which are NYPD cops, but also include firefighters and teachers — noted that when Adams announced the mandate lift, he left the door open to reinstate it again in the future.

“They want to see [their cases] through,” he said of his clients. “[They] want a judge to annul, vacate and void [their denials] and they want a judge to rule that they are entitled to an exemption so they never have to worry about this in the future.”

If the cases are allowed to play out, the employees can go after the city for attorneys fees and potentially lost wages, Mermigis said.

But it’s also about the principle.

“They are trying to have people forget how they treated their employees for over a year,” Mermigis said of city officials. “They are trying to wipe the slate clean.”

Other lawyers who represent public sector workers in similar cases say they also want their clients to have their day in court.

Attorney Christina Martinez – who is fighting some 20 cases for firefighters, cops and teachers – said: “Our clients have still been aggrieved. They still need to be made whole.”

Lawyer Jeannette Poyerd-Loiacono said the city’s attempt to get cases tossed as moot is a legal maneuver that she’s seen in two of her six open cases representing teachers and cops and she plans to oppose it.

“It’s a crafty ploy on their part to try to wiggle their way out of liability,” Poyerd-Loiacono said. “How simple would it be if all these cases could magically go away because they are moot?”

“You’re stuck with what you already decided,” she said of the city’s exemption denials. “There are damages and [my clients] are entitled to attorneys fees.”

About 1,780 city employees were shown the door for refusing to get vaccinated over the course of the pandemic. And while those workers can reapply, Adams has said they aren’t guaranteed their jobs, their prior seniority or back pay.

The lawyers also took issue with the fact that the newest Health Department order doesn’t actually rescind the mandate, but rather changes the language allowing workers to be unvaccinated at work – which they argue leaves the door open for it to be reinstated down the line.

Jimmy Wagner – another lawyer with at least four open vaccine mandate cases – said: “When an individual is under the threat of the reimposition of a mandate or an executive order, the issue can’t be moot.”

The city Law Department didn’t return a request for comment Thursday.