[T]he Cambridge spies did their greatest harm to Britain
not during their clandestine espionage in 1934-51, but in their
insidious propaganda victories over British government departments
after 1951. The undermining of authority, the rejection of expertise,
the suspicion of educational advantages, and the use of the words
"elite" and "Establishment" as derogatory epithets transformed the
social and political temper of Britain.
-- Richard Davenport-Hines. Enemies Within: Communists, the Cambridge Spies and the Making of Modern Britain (2018).