He is banned from driving on UK roads.
If they stop him they will ask his name and address and DOB etc, and it will come up telling them that he is banned.
If he starts waving a jamaican license at them, they'll ignore it.

Thats my opinion, I havent ever tried it, but im pretty sure that given that he as in individual is explicitly banned from UK roads, that wether he has another license or not, won't change that fact.