He is best remembered for his namesake role from 1973 to 1977 as the comically ferocious prison warder, Mr Mackay, in the British sitcom "Porridge" alongside the comedian and comedy actor Ronnie Barker. He also appeared in the film version of the series. The ensemble playing of Mackay, Barker, Richard Beckinsale and Brian Wilde, and the writing by Dick Clement and Ian La Frenais, made "Porridge" one of the most successful comedy series of the 1970s. He returned to the role of Mr Mackay, now nearing retirement from the Prison Service, in the first episode of "Going Straight" (1978), the sequel series to "Porridge".