A former de Blasio administration employee, who was once considered and rising young New York Democrat, will spend up to three years behind bars after pleading guilty to possessing kiddie porn Wednesday.

Jacob Schwartz, 31, looked sullen as Justice Steven Statsinger handed down the sentence that had been promised after the sicko in May copped to promoting a sexual performance by a child.

Following the brief hearing, the one-time computer programmer analyst in the city Department of Design and Construction was cuffed and led away by court officers.

Schwartz was terminated in May 2017 after getting busted for allegedly downloading more than 3,000 sick child-porn images and 89 videos from the internet involving girls as young as 6 months old.

The political perv was the president of the Manhattan Young Democrats and downstate regional vice president of the New York State Young Democrats before both groups abruptly cut ties with him when the allegations came to light.

Outside the courtroom, his father, labor lawyer and Democratic insider Arthur Schwartz, shoved a Post photographer and screamed, “Get the f–k away from me!”

Last month, the younger Schwartz sued the city for back pay, claiming he was owed more than $18,000 because he was paid in “comp time” instead of time and a half when he clocked more than 40 hours a week.

Schwartz was employed as a $66,360-a-year computer programmer analyst by the city for two years when he was arrested in May 2017.

The Manhattan federal lawsuit was filed by his father.

“They owed him money and he tried for two years to get paid,” the elder Schwartz told The Post.

The city will review the complaint, a Law Department spokesman said.

Speaking at his son’s arraignment in 2017, the elder Schwartz called his son’s case “a personal tragedy.”

“I understand these are serious charges,” he said. “He’s already in therapy for this.”