Mr. Walker, an Augusta Democrat who was once the Senate majority leader, was convicted in 2005 of 127 counts of fraud, tax evasion and abusing the power of his office. Federal District Judge Dudley H. Bowen Jr. sentenced him to more than 10 years imprisonment.
Mr. Walker began serving his sentence at a federal prison in Estill, S.C., in December 2005.
In a statement released to reporters Wednesday, family spokesman Kenneth Walker - who is not related to Charles Walker - said the former senator had petitioned the circuit court for an "en banc" appeal. A three-judge panel from the court unanimously rejected Charles Walker's initial appeal last month.
The petition for the en banc hearing was filed Friday.
Kenneth Walker also said Alan Dershowitz, a nationally known lawyer whose previous clients include O.J. Simpson and Mike Tyson, would join Charles Walker's defense team.
Mr. Walker's initial appeal to the circuit court had argued that four jurors were improperly seated, that the jury got the wrong instructions on the charge of mail fraud, that prosecutors were charging him with violation of state ethics laws and that Judge Bowen added too much time to his sentence.
The appeals court closely examined the racial makeup of the jury that convicted Mr. Walker after the prosecution used all of its opportunities to remove jurors from the pool to strike blacks. Mr. Walker's legal team, in turn, used their strikes to remove white men.
Judge Bowen accepted the prosecution's strikes but ruled that Mr. Walker's lawyers had improperly removed four jurors.
"While striking members of only one race does not always create an inference of purposeful discrimination, the sheer volume of strikes against one race is not easily attributable to chance," wrote Judge Charles R. Wilson, in the circuit court opinion upholding Judge Bowen's ruling.
But Judge Wilson said Judge Bowen's original decision deserved the benefit of the doubt.
Brandon Larrabee can be reached at brandon. firstname.lastname@example.org or (678) 977-3709.