Suspicion and secret confession
Some people knew of Blunt's role as a Soviet spy long before his public exposure. According to MI5 papers released in 2002, Moura Budberg reported in 1950 that Blunt was a member of the Communist Party of Great Britain, but this was ignored. According to Blunt himself, he never joined because Burgess persuaded him that he would be more valuable to the Soviet cause by working with Burgess. He was on friendly terms with Sir Dick White, the head of MI5 and later MI6, in the 1960s, and they used to spend Christmas together with Rothschild in the latter's Cambridge residence.
Blunt's KGB handlers had also become suspicious at the sheer amount of material he was passing over, suspecting him of being a triple agent. Later, he was described by a KGB officer as "ideological shit".
With the defection of Burgess and Maclean to Moscow in May 1951, Blunt came under suspicion. Burgess returned on the RMS Queen Mary to Southampton after being suspended from the British Embassy in Washington, D.C. for his conduct. He was to warn Maclean, who now worked in the Foreign Office but was under surveillance and isolated from secret material. Blunt collected Burgess at Southampton Docks and took him to stay at his flat in London, although he later denied that he had warned the defecting pair. Blunt was interrogated by MI5 in 1952 but gave away little if anything. Arthur Martin and Jim Skardon interviewed Blunt eleven times after 1951, but Blunt had admitted nothing.
Blunt was greatly distressed by Burgess' flight and, on 28 May 1951, confided in his friend Goronwy Rees, a fellow of All Souls College, Oxford, who had briefly supplied the NKVD with political information in 1938–39. Rees suggested that Burgess had defected because of his virulent anti-Americanism and belief that the United States would involve Britain in a Third World War, and that he was a Soviet agent. Blunt suggested that this was not sufficient reason to denounce Burgess to MI5, pointing out that "Burgess was one of our oldest friends and to denounce him would not be the act of a friend." Blunt quoted E. M. Forster's belief that country was less important than friendship, arguing that "Burgess had told me he was a spy in 1936 and I had not told anyone".
In 1963, MI5 learned of Blunt's espionage from Straight, whom he had recruited. Blunt confessed to MI5 on 23 April 1964. The Private Secretary to the Sovereign was informed shortly thereafter, but Queen Elizabeth II herself was not officially informed until 1973. Blunt also named Cairncross, Jenifer Hart, Phoebe Pool, Peter Ashby, Brian Simon and Leonard Henry Long as spies. Long had also been a member of the Communist Party and an undergraduate at Trinity College, Cambridge. During the war, he served in MI14 military intelligence in the War Office, with responsibility for assessing German offensive plans. He passed analyses but not original material relating to the Eastern Front to Blunt.
According to his obituary in The New York Times, Blunt acknowledged that he had recruited spies for the Soviets from among young radical students at Cambridge, passed information to the Russians while he served as a high-ranking British intelligence officer during the Second World War and had helped two of his former Cambridge students who had become Soviet moles, Burgess and Maclean, escape in 1951 just as their activities were about to be exposed.
Blunt was convinced that his confession would be kept secret. "I believed, naively, that the security service would see it, partly in its own interest, that the story would never become public", he wrote. In return for a full confession, the British government agreed to keep his espionage an official secret, though only for fifteen years, and granted him full immunity from prosecution. Blunt was not stripped of his knighthood until the Prime Minister, Margaret Thatcher, announced his treachery in 1979.
According to the memoir of MI5 officer Peter Wright, Wright had regular interviews with Blunt from 1964 onwards for six years. Prior to that, he had a briefing with Michael Adeane, the Queen's private secretary, who told Wright: "From time to time you may find Blunt referring to an assignment he undertook on behalf of the Palace – a visit to Germany at the end of the war. Please do not pursue this matter. Strictly speaking, it is not relevant to considerations of national security."
For unknown reasons, the Prime Minister, Alec Douglas-Home, was not informed of Blunt's spying, although the Queen and Conservative Home Secretary Henry Brooke had been fully informed. In November 1979, Margaret Thatcher informed Parliament of Blunt's treachery and the immunity deal that had been arranged.
Blunt's life was little affected by the knowledge of his treachery. In 1966, two years after his secret confession, Noel Annan, provost of King's College, Cambridge, held a dinner party for Labour Home Secretary Roy Jenkins, Ann Fleming (widow of James Bond author Ian Fleming), and Victor Rothschild and his wife Tess. The Rothschilds brought their friend and lodger – Blunt. All had had wartime connections with British intelligence; Jenkins at Bletchley Park.