Federal prosecutors say Tony Rezko deserves to spend up to 15 years in prison for his crimes in two separate cases and that he damaged his own credibility by lying to the court.

Prosecutors for the first time publicly addressed why they never called him to the witness stand after he began cooperating in 2008. They say over 19 meetings with them, he didn't fully tell the truth about his own wrongdoing until he was confronted by agents with new information. Prosecutors said juries would never have accepted his word.

"Rezko's cooperation was heavily tainted by the timing of when he decided to cooperate, by his repeated lies to
judges, and by his pervasive and sustained lies made to the government over the first
several months of his purported cooperation with the government," prosecutors wrote.

The recommendation is in drastic contrast from the time served that Rezko's lawyers are asking U.S. District Judge Amy St. Eve to impose at his Nov. 22 sentencing. Prosecutors say they believe Rezko should face 11 to 15 years in prison for a kickback case before St. Eve and a separate loan fraud case that was before U.S. District Judge James Zagel.

The government's recommendation is significantly more steep than the roughly five and a half years that serial conman and drug abuser Stuart Levine faces. Levine is accused of conspiring with Rezko during Rod Blagojevich's administrations to win kickbacks from state deals.

"From the government's perspective, the major difference between Levine and
Rezko is not the quality or quantity of their past crimes - both Rezko and Levine are
guilty of terrible crimes," prosecutors wrote. "The major difference between Levine and Rezko is that
Levine's cooperation with the government has been truly remarkable, while Rezko's has
not. For his many faults, Levine's cooperation is directly responsible for convictions in
difficult and important cases against, among others, Rezko, William Cellini, and Edward
Vrdolyak."

They say Levine cooperated wore a wire and cooperated "pro-actively." Levine has testified in two major trials. But Rezko's lawyers argue, that prosecutors could have called Rezko to testify -- he was prepared to do so -- but they never did.