As many as 73,000 disqualified novice drivers could have returned to the road illegally over the past decade, according to Government figures.
Around 160,000 have been banned under the New Drivers Act since its introduction in June 1997. The law automatically revokes the licences of drivers who amass six penalty points in their first two years as a fully qualified motorist, meaning that they have to retake their driving test.
However, official records have revealed that since the law came into force, only about half of those banned have subsequently retaken and passed their retest.
Many of those who have not done so are now suspected of driving illegally without a valid licence.