New York City's largest police union is suing Mayor de Blasio to block the NYPD’s release of body camera footage — claiming its disclosure poses civil rights concerns for cops and civilians.

"The basis of this suit is simple: we're suing to prevent the Mayor and the NYPD from arbitrarily and illegally releasing body camera footage,” Patrolmen’s Benevolent Association President Patrick Lynch said of the Manhattan Supreme Court lawsuit, which was obtained by the Daily News.

“This footage has serious implications not only for the safety and due process rights of police officers, but for the privacy and rights of members of the public, as well. The Mayor and the NYPD have shown a reckless disregard for these concerns by circumventing the existing process set up by the State Legislature and selectively releasing portions of videos to suit their own interests.”

While the NYPD does not allow the blanket release of body camera footage, the department has agreed to release video on a case-by-case basis.

Lynch wants a judge to decide whether requested body cam footage should be released, rather than the NYPD.