CHICAGO (CBS) — Former Gov. Rod Blagojevich is asking to play wiretap recordings that were previously placed under seal when he’s sentenced next month.

Blagojevich’s attorneys have requested that U.S. District Judge James Zagel allow them to play recorded conversations that were not heard at the former governor’s trial, in an effort to gain a more lenient sentence.

READ MORE: FBI Seeking Public's Help Finding Devontay Anderson; Feds Say Third Suspect Charged In Killing Of Jaslyn Adams Fled State To Avoid Prosecution

The defense said they were blocked from playing those tapes at trial, largely because the judge found them to be immaterial or irrelevant to the case.

But the defense argues they are critical to determining a fair sentence for Blagojevich, claiming they “show Mr. Blagojevich’s state of mind and lack of ill intent.”

Defense attorneys listed 180 separate tapes in an attachment to their motion, although several tapes on the list were played at trial.

Defense attorneys said that they do not want to play any wiretap recordings in their entirety, only brief portions of the tapes.

“The portions of conversations which the defense seeks to include in its sentencing filing and at the hearing are critical to the defense argument and to the protection of Mr. Blagojevich’s constitutional rights,” the defense wrote.

Blagojevich was convicted of 17 corruption counts at his retrial this summer, including allegations that he tried to sell or trade an appointment to President Barack Obama’s former U.S. Senate seat. At his first trial last year, jurors were deadlocked on all but one count, a conviction for lying to the FBI.

READ MORE: 'I Was Excited': Kids Talk About Getting Their First COVID Shot

The former governor is set to be sentenced on Dec. 6. He plans to speak in his own defense and defense attorneys have said the sentencing hearing could take two days.

Earlier this week, Blagojevich’s top fundraiser, Antoin “Tony” Rezko, was sentenced to 10 ½ years in prison for a shakedown scheme tied to the former governor. Rezko was convicted three years ago of fraud and money laundering and scheming to squeeze millions of dollars in kickbacks from companies that were seeking state business while Blagojevich was governor.

Prosecutors are expected to seek an even stiffer sentence for Blagojevich.

The wiretap recordings of Blagojevich’s conversations were a central part of the case against him.

Defense attorneys have asked repeatedly to unseal a number of tapes that they claimed would prove Blagojevich’s innocence, but Zagel has ruled that most of the tapes the defense wanted to play were irrelevant, because Blagojevich could better testify to his own state of mind.

The defense has also argued the tapes would prove that Blagojevich was trying to appoint Illinois Attorney General Lisa Madigan to President Barack Obama’s vacated Senate seat in order to get her father, House Speaker Mike Madigan, to pass the governor’s legislative agenda.

MORE NEWS: Small Plane Lands On I-355 At 159th Street In New Lenox; Pilot, 3 Passengers Suffer Injuries

But Zagel has scoffed at those claims, calling them a “red herring,” saying that it was clear from the evidence that no deal could have been struck with Madigan because no one ever approached either the speaker or the attorney general about it.