CHICAGO (CBS) — Federal prosecutors have asked a judge to prevent former Gov. Rod Blagojevich’s defense attorneys from arguing that playing all the tapes of FBI wiretaps of his conversations would exonerate Blagojevich at upcoming retrial.

Blagojevich has repeatedly said in public that he would be cleared of all corruption charges if prosecutors were forced to “play all the tapes” of wiretap recordings made by the FBI. He has publicly suggested that certain unheard tape recordings contain proof of his innocence.

Prosecutors have filed a motion seeking to bar Blagojevich’s defense attorneys from making similar suggestions to the jury at his retrial.

“Not only do questions designed to elicit such evidence serve no legitimate purpose, they focus the jurors’ attention on evidence that is not before them, and act as a suggestion that other evidence, favorable to the defense, is being withheld from them.” prosecutors wrote in their motion.

U.S. District Judge James Zagel ruled before the former governor’s first trial that neither side could suggest there was evidence that jurors were not allowed to hear, noting that either side could play tapes that he ruled would be pertinent to the case.

Federal prosecutors have filed a motion seeking a similar ruling for Blagojevich’s retrial, set to begin later this month.

“Beginning before the first trial of this case and continuing through the present, defendant has made a campaign of asserting (falsely) … that recordings of intercepted conversations not played in the first trial would exonerate defendant, and of suggesting that the government intentionally chose and presented recordings and portions of recordings out of context, so as to mislead the jury and the public regarding defendant’s statements and conduct,” prosecutors wrote.

“This Court has made clear that the defendant is free to propose the introduction of any recorded conversations he wishes, and that any such recordings may be presented to the jury, so long as they are relevant and otherwise admissible,” prosecutors added. “The Court has also made clear that the Court, rather than the government, is the final arbiter of what is, and what is not, presented to the jury. Yet the defense has continued to suggest otherwise.”

Blagojevich’s retrial is slated to start in less than two weeks, on April 20. At his first trial last summer, Blagojevich was convicted of lying to federal agents, but jurors deadlocked on 23 other counts against him. Prosecutors have since dropped three of those counts in an effort to simplify their case.

The former governor is accused of, among other things, trying to get a campaign contribution, a Cabinet position with the Obama administration or another lucrative job in exchange for appointing someone to President Barack Obama’s old U.S. Senate Seat in 2008.

Prosecutors also were seeking to block defense attorneys from eliciting testimony about what Blagojevich tried to do with the Senate seat after news reports were published revealing that the FBI had been recording Blagojevich’s conversations.

The government said it does not plan to introduce any evidence regarding discussions Blagojevich had about the Senate seat after Dec. 5, 2008, when it became known that the feds were taping him.

“The government’s rationale is that defendant’s actions after the wiretaps became public were mostly acts of concealment,” prosecutors wrote, “and in any event are not necessary to prove the defendant’s affirmative efforts to bring his attempt to obtain financial benefits in exchange for the Senate seat appointment to fruition.”

The prosecution’s motion will be discussed at an upcoming hearing on Thursday.