Unless you can prove that you were not in fact driving or were not the subject of a period of disqualification, defences are limited. However, a valid defence of Necessity or Duress is available. The defence is only available where the disqualified person is able to establish that he drove because of an immediate danger to himself or another person.
Problems arise where people are unaware that they are disqualified. This may happen where a person has:
been disqualified in their absence; or been ordered to re-sit their test following a period of disqualification, or simply made a mistake about the dates of disqualification.
It is not a defence that a person did not know that they were disqualified or that they made a genuine mistake. However, such an explanation may serve to reduce the penalty that the court imposes.