Mackay is a neurotic and tough prison warden whose constant obsession in life is to catch out Fletcher. The rivalry between Fletch and Mackay was a thing of comedy legend. Fletch's sly tactics in misdeeds ranging from fixing boxing matches, stealing pills from the prison doctor and eggs from the prison farmyard right through to finding new and imaginative ways to stick two fingers up at Mackay and get away with it, were specially designed to get up Mackay's nose. In return, Mackay's frenzied attempts to catch Fletch out, when fruitful, gave Mackay a level of smugness and satisfaction which was only accentuated by Fletch's hostility and skulking.
Mackay's temper is agitated by the constant suspicion he has of Fletch, and his despair at the leniency of his colleague Mr Barrowclough.
Mackay's homeland of Scotland served as a constant source of entertainment for Fletcher who is constantly on the lookout for an opportunity to stick up two fingers at Mackay - both metaphorically and literally. In one episode Mackay questioned Fletch on whether he felt he was middle class. Fletch responded 'I did, until I visited Scotland. Now I think I'm middle class.'
Mr Barrowclough was a character in the popular BBC sitcom Porridge.
Unlike MrMackay, whose harsh and confrontational methods Mr Barrowclough disapproves of (though he dare not make this known to MrMackay), Barrowclough is a timid, sympathetic man who firmly believes that the role of prison is to rehabilitate rather than punish.
Mr Barrowclough does not seem to be cut out for the life of a prison warden, and how he came to be in this line of work remains a mystery.