URGENT: Contravention for driving without insurance.

magpiecottage

I think a court would be unlikely to convict if the defendant could prove that a certificate of insurance was in force at all times the vehicle was on the public highway.

The problem is, though, that, according to the OP, the defendant drove off and at some time between then and getting stopped the policy went in to force.

If that is correct then in that gap an offence was committed. If the prosecutor can prove that then they will probably get a conviction. If the defendant was stopped a distance from home that it is beyond all reasonable doubt they could not have reached after the policy came into force then the case is proven.