Prosecutors called for Dean Skelos to get a prison sentence at least “approaching” 12 1⁄2 to 15 1⁄2 years in a stern sentencing letter on Monday that slammed the former Republican Senate majority leader for a corruption scheme that did “abiding damage to the democratic process.”

The government also called for a fine exceeding $350,000 to take a sizable chunk out of his liquid assets of more than $2 million and his lifetime public pension of $95,000 a year, and urged a sentence that approaches at least 10 years for his son and co-defendant, Adam Skelos.

“By almost any metric, the instant offenses were among the most serious public corruption crimes committed in New York State in recent memory,” the government said. “Accordingly, justice in this case requires a stiff and substantial sentence for each defendant.”

Dean Skelos, 68, and Adam, 33, both of Rockville Centre, were convicted last year in Manhattan federal court of conspiring to use Dean’s power to help Adam get work from a real estate developer, a malpractice insurer and an environmental firm. Sentencing is set for April 28.

Lawyers for the two both asked for leniency and no jail time in filings last month, arguing that their crimes were the product of a lifetime of psychological struggles, and that the disgrace of their convictions punished them enough.

They argued Dean Skelos’ crimes stemmed from his extraordinary devotion to Adam, whom Dean adopted after learning he was infertile. Adam said he struggled his whole life with substance abuse, is separating from his wife and feared his autistic children would suffer if he went to jail.

But prosecutors blasted those arguments, telling U.S. District Judge Kimba Wood that Skelos was “in some measure” motivated by his needy son, but it was no excuse for corruption.

advertisement | advertise on newsday

“A dramatic variance of the type Dean Skelos seeks . . . would not be just,” the government said. “Dean Skelos is and should be held responsible for his actions. He had an abundance of choices and ways to help his son, yet he chose the path of crime and of betrayal of his oath, over and over again.”

The government also dismissed the ex-senator’s claims that his loss of office and disgrace were sufficient punishment.

“He has steadfastly refused to show remorse for his violation of the public trust, persisted in characterizing his criminal conduct as simply the result of loving his son too much, complaining of humiliation, and pointing fingers at the immunized witnesses,” prosecutors wrote.

For both father and son, the government said imprisonment “within or approaching” the range of federal sentencing guidelines — 151 to 188 months for Dean, and 121 to 151 for Adam — would put them near the high end of recent New York corruption sentences.

But prosecutors urged a fine for Dean Skelos well above the recommended range of $35,000 to $350,000, noting that the fine could go as high as $2 million, and Skelos had $175,000 in cash, $975,000 in securities, and houses in Long Island and Florida worth $735,000. He is also, they said, entitled to a $95,000-a-year pension, which could quickly pay off $350,000.

“It would be gravely unjust,” prosecutors said, “if a fine in a public corruption case were so small that the defendant could easily pay it by using pension money paid for by the victims of his crimes and owed to him from holding the same office that he corrupted.”