Your dad will be fine to supervise. The only criteria is that you are 21 or over, and it is 3 years or more since the supervisor passed their test. The fact that he WAS disqualified does not come into it.
I doubt he'll drink and drive again specially when teach us *his sons* Thanks for your reply. Another question I thought "supervisor" should have their full license for 3 years not prior to when they passed their driving test but he got his new license not 3 years ago.The only thing for him to worry about is to make sure he does not drink himself, then act as supervisor. The same drink drive limits apply to the supervisor as the driver......