Raleigh, N.C. — Former Democratic presidential contender John Edwards asked Thursday for a two-month delay in his trial on alleged campaign finance violations, citing an undisclosed medical condition among other reasons.

Edwards, a former U.S. senator from North Carolina, faces six felony and misdemeanor charges stemming from the nearly $1 million paid by two donors to help hide and care for his pregnant mistress, Rielle Hunter, during his 2008 run for the White House.

The trial is set to begin Jan. 30, but Edwards' attorneys said in a motion that they don't have enough time to prepare for such a complex case and that failure to delay the trial "would be likely to result in a miscarriage of justice."

Information about the medical condition was provided to the court under seal, according to the motion.

Defense attorneys won a small victory in the case last week when U.S. District Judge Catherine Eagles denied prosecutors' attempts to prevent two potential defense witnesses from testifying.

Edwards' lawyers want Scott Thomas and Robert Lenhard, two former commissioners of the Federal Election Commission, to testify about their doubts that the donations to help Hunter violated campaign finance laws.

Federal prosecutors argued that witnesses shouldn't be allowed to offer their opinions on election law, saying the judge is responsible for interpreting the law in the case. Eagles said she wants to hear the government's case against Edwards before deciding whether to allow Thomas and Lenhard to testify.