The chairman of selectors is fighting to have overturned the pounds 2,000 fine handed out by the Test and County Cricket Board's discipline committee in June.
Illingworth was found guilty of bringing the game into disrepute over newspaper articles taken from his controversial book One-Man Committee.
He was also charged with making public statements "that may be prejudicial" to the interests of cricket, notably in passages that detailed his falling out with Devon Malcolm in South Africa last winter, and in revealing accounts of selection meetings.
Illingworth initially had 28 days in which to appeal, and the 64-year- old former England captain was so outraged by his treatment by Lord's that he decided to prolong an issue which has soured his final summer of active involvement in the game he loves.
A four-man panel will hear Illingworth's argument that the details disclosed by the book merely allowed him a right of reply to Malcolm's allegations, also made in a newspaper article. Malcolm escaped censure, even though he was in breach of his tour contract.
Judge Desmond Perrett, QC, will chair a panel which includes Frank Chamberlain, the former TCCB chairman, Frank Elliott, chairman of the National Cricket Association, and John Warr, the former Middlesex fast bowler who is now treasurer of the MCC.