Based on the same real life events as Another Country (1984), Cambridge Spies (2003), History in Faces: Cambridge Five (2011), Philby, Burgess and Maclean (1977), A Question of Attribution (1991), An Englishman Abroad (1983), Tinker Tailor Soldier Spy (2011), Tinker Tailor Soldier Spy (1979), Blade on the Feather (1980), Blunt (1987), The Jigsaw Man (1983) and influenced the source novels of The Fourth Protocol (1987), The Innocent (1993) and others works such as A Different Loyalty (2004) and Olding (2019), even in minor form like in The Imitation Game (2014).
Although he was delighted to have won a BAFTA for his performance, John Le Mesurier commented that the aftermath proved "something of an anticlimax. No exciting offers of work came in".
John Le Mesurier wrote in his memoir that he "was very, very scared" that "he wouldn't be able to pull it off". He would later call the role "the best part I ever had on TV".
John Le Mesurier would ruefully deflect congratulation on his BAFTA win by pointing out that the inscription it carried was the somewhat less-than-complimentary "John Le Mesurier - Traitor".