Attorneys for John Edwards  are seeking to delay his criminal trial -  in part because the former Democratic presidential candidate has developed a medical  issue that cannot be resolved before the scheduled trial date in late January.

In a document filed today in federal court in North Carolina, the defense lawyers wrote that Edwards "has unexpectedly encountered a medical issue which makes the trial of this case in the January 2012 criminal term extraordinarily difficult."   The defense was seeking a 60-day delay.

The details of the medical condition were not revealed in the public portion of the court filing but were provided to the court and the prosecutors in a sealed exhibit accompanying the defense motion.   Edwards' attorneys did not immediately respond to a request for comment.

Chuck Burton/AP Photo

Edwards was charged in June in a six-count indictment alleging his complicity in a scheme to solicit - from two wealthy supporters - hundreds of thousands of dollars that were used to support and seclude Rielle Hunter, with whom Edwards had an extra-marital affair and fathered a child.    The government contends the money was spent to protect Edwards' campaign, in violation of election laws.   Edwards pleaded not guilty to all the charges, and his defense team contends that the government's case is based on flawed interpretations of campaign finance laws.

Aside from the medical issue, the defense team argues that - given the sheer volume of material handed over to them by the government - they would have inadequate time to prepare  if the trial were to proceed in January.     According to the motion, the prosecutors have produced more than a half a million pages of documents since August.   "It is impossible for defense counsel to prepare adequately or to provide constitutionally effective assistance of counsel in so short a period," the motion states.

The government immediately filed a response opposing the delay on the grounds of inadequate time to prepare - but took no position in regards to the medical condition cited by Edwards.