As Dean Skelos and his ne’er-do-well son, Adam, gear up for sentencing Thursday, the elder Skelos has hired noted appeals lawyer Alexandra Shapiro to help him argue his way out of prison.

Shapiro, of law firm Shapiro Arato, helped get hedge-fund manager Anthony Chiasson’s insider-trading conviction tossed by a Manhattan federal appeals court in December 2014.

Prosecutors with Manhattan US Attorney Preet Bharara’s office have asked that the disgraced ex-state Senate majority leader be hit with a $500,000 fine and a sentence “approaching” 12 to 15 years.

Adam, 33, faces between 10 and 12 years prison.

Lawyers for the two have asked Manhattan federal Judge Kimba Wood for probation, citing Dean’s service to the community and Adam’s two ­autistic sons.

The Skeloses were convicted in ­December of bribery, corruption and conspiracy after prosecutors played tapes showing that the Long Island Republican strong-armed companies into paying Adam more than $330,000.

The Skeloses “demonstrated a brazen pattern of pressuring, bullying and threatening those with substantial official business before the New York state Senate in order to extract payments for Adam Skelos,” the government said in its sentencing report to the judge.