Leeds' lawyers are attempting to convince a three-man panel that the League acted outside their jurisdiction when docking the club 15 points at the start of this season as punishment for allegedly breaking competition rules on insolvency.
If the sanction is overturned and Leeds are given all of their points back, the consequences in Coca-Cola League One could be far-reaching.
Several of the club's promotion rivals, including Carlisle and Doncaster, have already threatened legal action depending on the outcome, which could see Leeds move into an automatic promotion place.