Elizabeth II kept in dark over Palace traitor Anthony Blunt

Queen Elizabeth II was left in the dark for almost a decade over the full scale of the treachery of one of her most senior courtiers, according to newly-released official files.

In 1964, Sir Anthony Blunt, the surveyor of the Queen’s pictures and distinguished art historian, finally confessed he had been a Soviet agent since the 1930s having been recruited, when he was a young don at Cambridge, into one of the most notorious spy rings of the 20th century.

As a senior MI5 officer during the Second World War, Blunt had passed vast quantities of secret intelligence to his KGB handlers but was nevertheless allowed to maintain his position at the heart of the British establishment amid fears of a major scandal if he was sacked and the truth became public.

When the Queen was finally told the full story in the 1970s, she was characteristically unflappable – taking it “all very calmly and without surprise” – according to declassified MI5 files released to the National Archives in Kew, west London.

The decision to ensure she was properly informed came amid growing concern in Whitehall that the truth would inevitably come out when Blunt – who had been seriously ill with cancer – died and journalists, who were sniffing around the story, were no longer restrained by concerns of libel.

In February 1973, prime minister Edward Heath ordered preparations to be put in place for dealing with the expected torrent of negative publicity, including instructions to Sir Martin Charteris, the Queen’s private secretary, to inform the monarch.

On March 19, MI5 director general Michael Hanley reported that the cabinet secretary Sir Burke Trend had shown him a “personal manuscript letter” from Sir Martin confirming she had finally been told.

“Charteris wrote that he had spoken to the Queen about the Blunt case. She took it all very calmly and without surprise,” Mr Hanley noted.

According to the official history of MI5 by Professor Christopher Andrew, Mr Heath was later informed the Queen had not been entirely in the dark as she had been told “in more general terms about a decade earlier”.

However, she apparently made no mention of any earlier briefing, simply acknowledging she had been aware of suspicions about Blunt when his fellow spies, Guy Burgess and Donald Maclean, fled to Russia in 1951.

“Obviously somebody mentioned something to her in the early 1950s, perhaps quite soon after her accession,” Mr Hanley wrote.

Four months earlier, in November 1972, Mr Hanley had met Sir Martin to urge the Palace to sever its links with Blunt.

Sir Martin, however, refused, saying there was little point as Blunt’s position was anyway drawing to a close.

“Charteris thought the Queen did not know and he saw no advantage in telling her about it now; it would only add to her worries and there was nothing that could done about him,” Mr Hanley reported.

“Contrary to what Blunt may have said in the past, Charteris affirmed that the Queen was not at all keen on Blunt and saw him rarely.”

The files suggest that, up until that point, contacts between MI5 and the Palace over Blunt had been sporadic.

In April 1964, the then director general, Sir Roger Hollis, briefed Sir Martin’s predecessor, Sir Michael Adeane, just as they were about to confront Blunt with the new evidence of his treachery which finally led him to confess.

“Sir Michael Adeane thanked me for letting him know the position,” Sir Roger reported.

“He said that he did not propose to tell anyone else about it, but asked that we should let him know if there later appeared any possibility of publicity so that he could at that stage take the necessary action.”

Sir Michael was apparently not briefed again until October 1967, more than three years after Blunt finally owned up, and then only because there was a “risk of publicity” due to a Sunday Times investigation into another of the Cambridge spies, Kim Philby.

Miranda Carter, who wrote a 2001 biography of Blunt, said she believed the Queen would have been told informally some time after 1965.

“It’s the job of a private secretary to a monarch to inform them and protect them. It seems to me that she probably needed to know about Blunt in order to know how to behave if she came into contact with him,” she said.

Remarkably, the Queen’s apparent ignorance of what was going on was matched by that of her then prime minister, Sir Alec Douglas-Home, who also was not informed of Blunt’s admission.

In an extraordinary misjudgment for which he later apologised, home secretary Henry Brooke, who was in in the know, chose not to tell him because he did not want to “add to his burdens”.

Overall, the files suggest MI5 was deeply reluctant to share information about the case with anyone in government – as late as July 1965 Sir Burke had still not been informed, nor had any ministers in the new Labour government which had taken office the previous October.

Blunt was finally unmasked by prime minister Margaret Thatcher in a Commons statement in 1979. He died in 1983 aged 75 having been stripped of his knighthood.

The files are being released now ahead of the opening in the spring of a major new exhibition focusing on the work of MI5 being staged at the National Archives.

Exhibits will include a vivid report of Blunt’s interview when he finally owned up after MI5 officer Arthur Martin confronted him with testimony from Michael Straight, a young American whom Blunt had recruited to work for the Russians in the 1930s.

“He sat and looked at me for fully a minute without speaking. I said his silence had already told me what I wanted to know. Would he now get the whole thing off his chest,” Mr Martin wrote.

“Blunt’s answer was, ‘Give me five minutes while I wrestle with my conscience’. He went out of the room, got himself a drink, came back and stood at the tall window looking out over Portman Square.

“I gave him several minutes of silence and then appealed to him again to get it off his chest. He came back to his chair and told me this story.”