He said: “I suppose maybe the person who wrote the question wanted to hear that there’s some rivalry or whatever – the truth is they are our friends, they are our colleagues.”
Answering questions at the National Archives, Sir Ken said both agencies along with the police and others work together in a team “each doing our particular thing, the thing that we are specialists at – to keep the country safe together”.
The series is based on the best-selling novel Slow Horses by Mick Herron and premiered in 2022, with season six set to be released in September, and a seventh season set for release in 2027.
The show stars Sir Gary as Jackson Lamb, the shabby and dischevelled yet competent head of Slough House whose trademark move is breaking wind.
In an interview with the BBC in 2024 to promote the show’s fourth series, Sir Gary described the show as: “The sort of slightly shady, dirty side of espionage. It’s your PG Tips, Tescos version of it I guess.”
Slow Horses also stars Dame Kristin Scott Thomas as MI5 Director General Diana Taverner, Jack Lowden as agent River Cartwright, and SirJonathan Pryce as Lowden’s on-screen grandfather and retired British senior intelligence official.