The NYPD on Wednesday announced plans to arrest three vagrants in an attack on a lone cop inside a Manhattan subway station — and admitted it never told prosecutors about the incident when the men were later busted for sleeping on the platform.

Manhattan DA Cyrus Vance Jr. came under blistering criticism when prosecutors dropped illegal-sleeping charges against the three men and two others Monday night, with the Patrolmen’s Benevolent Association and various pols accusing him of turning the subways over to lawbreakers.

Vance spokesman Danny Frost said the DA’s office never would have declined to prosecute the men if it knew about the allegations, even if there wasn’t yet enough evidence to charge them in the attack.

Video of the disturbing incident shows Officer Syed Ali using a collapsible baton to fend off several drunken homeless men he confronted in the East Broadway station after a female subway rider told him that she’d been harassed by the group.

None of the men were charged following the incident — during which one of them tumbled onto the tracks — but five were sent for hospital treatment “due to their highly intoxicated condition,” the NYPD said Wednesday.

After the video was posted online, cops went back to the station Monday morning and busted all five for sleeping on the platform in violation of city law, but they were freed when prosecutors dropped the charges under terms of a 2016 accord with the NYPD.

“At the time of the arrest for the Local Law on 12-24-18, the Manhattan District Attorney’s Office was not made aware of the attempted assault of the police officer that took place the prior night on 12-23-18,” NYPD spokeswoman Sgt. Jessica McRorie said in a prepared statement.

Two of the men face charges of riot and obstructing governmental administration, while a third man faces those charges and attempted assault, McRorie said.

All three are wanted by the NYPD.