Traitor is a BBC

BBC

The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...

 television drama written by Dennis Potter

Dennis Potter

Dennis Christopher George Potter was an English dramatist, best known for The Singing Detective. His widely acclaimed television dramas mixed fantasy and reality, the personal and the social. He was particularly fond of using themes and images from popular culture.-Biography:Dennis Potter was born...

, which featured in the Play for Today

Play for Today

Play for Today is a British television anthology drama series, produced by the BBC and transmitted on BBC1 from 1970 to 1984. During the run, more than three hundred programmes, featuring original television plays, and adaptations of stage plays and novels, were transmitted...

on 14 October 1971.

It features the prominent British comedy actor John Le Mesurier

John Le Mesurier

John Le Mesurier was a BAFTA Award-winning English actor. He is most famous for his role as Sergeant Arthur Wilson in the popular 1970s BBC comedy Dad's Army.-Career:...

, in a straight acting role, as Adrian Harris, a character loosely based on Kim Philby

Kim Philby

Harold Adrian Russell "Kim" Philby was a high-ranking member of British intelligence who worked as a spy for and later defected to the Soviet Union...

, although he may also contain elements of Guy Burgess

Guy Burgess

Guy Francis De Moncy Burgess was a British-born intelligence officer and double agent, who worked for the Soviet Union. He was part of the Cambridge Five spy ring that betrayed Western secrets to the Soviets before and during the Cold War...

. There is an incident based on the Volkov incident in Philby's autobiography.

Potter revisited the subject of the Cambridge spies

Cambridge Five

The Cambridge Five was a ring of spies, recruited in part by Russian talent spotter Arnold Deutsch in the United Kingdom, who passed information to the Soviet Union during World War II and at least into the early 1950s...

 in his drama Blade on the Feather

Blade on the Feather

Blade on the Feather is a television drama by Dennis Potter, broadcast by ITV on 19 October 1980 as the first in a loosely-connected trilogy of plays exploring language and betrayal...

(1980).