In the latest series of The Crown, the Queen hears rumours that Harold Wilson, her prime minister, is secretly working for the Soviet Union. Officials then reassure her that he isn't. But what did MI5 really think?
Let me guess, Wilson was a Labour prime minister?
Yes, he was a grammar school boy from Huddersfield who went to Oxford and was a Labour prime minister from 1964 to 1970, and again from 1974 to 1976. With his Yorkshire vowels, he came to power promising a break with the old establishment.
The establishment wouldn't like that. But were there really people who suspected him of spying?
It's complicated, as I'll explain in a moment. But Wilson definitely thought a group of rogue right-wing officials believed there was a pro-Moscow cell in No. 10. His counter-accusation was that they were plotting against him, had worked with US and South African intelligence to smear him, and had withheld information about an establishment plot to overthrow him.
Did he make these allegations in a string of angry early-morning tweets?
Very funny. A few weeks after he quit as prime minister in 1976 Wilson summoned two BBC journalists to his home and told them democracy was under threat. He said they should investigate, and offered to help them. "I see myself as the big fat spider in the corner of the room," he said. "Sometimes I speak when I'm asleep. You should both listen. Occasionally when we meet I might tell you to go the Charing Cross Road and kick a blind man. That blind man may tell you something."
Amazing. Sounds like he'd completely lost the plot.
Actually, he may have hoped this would become the plot of a bestseller. The world had been transfixed by the Watergate scandal in the US - the story of a break-in at the Democratic National Committee headquarters in Washington and a cover-up by the White House, which led to the resignation of President Richard Nixon. The Washington Post reporters who broke the story had received leads from a mysterious insider they called Deep Throat. It's possible that Wilson hoped Fat Spider would be the new Deep Throat.
OK. So he thought MI5 had him down as a Communist spy. But I asked if you they really did?
At the time Fat Spider story came out, the general attitude was "this is paranoid stuff", says Dan Lomas, who teaches a course on the so-called Wilson plots at Salford University. But in the 1980s a disgruntled former MI5 officer called Peter Wright published a book called Spycatcher, in which he claimed he was a member of an MI5 clique that had plotted to force Wilson's resignation - because they were convinced he was a Communist spy.
Did Wright and his clique have any evidence for this?
Barely any. In the 1940s and 50s, Wilson made a dozen trips to the Eastern bloc - first as trade minister, and then in opposition, when he worked as an adviser to a timber company. Wright became convinced Wilson must have been compromised or recruited as a spy on one of these visits: "It was the number of times he went," the ex-spy told the BBC's Panorama programme in 1988. Wilson was also friends with a number of businessmen with Eastern European connections, such as raincoat manufacturer Joseph Kagan and publishing tycoon Robert Maxwell, whose loyalties were considered suspect by some within MI5.
Also, in the early 1960s, a Soviet defector called Anatoly Golitsyn had told his debriefers that Wilson was a spy and that Hugh Gaitskell, Wilson's predecessor as Labour leader, had been assassinated to make way for him. The claim was rejected by MI5's director general - but it was believed by Wright, as well as CIA counterintelligence chief James Jesus Angleton.
It later became clear, following the defection of KGB archivist Vasili Mitrokhin in 1992, that Wilson had once been on a list of politicians the KGB planned to target - but Wright would not have known this in the 1970s, he could only have guessed. (The Mitrokhin archive also made clear that nothing came of the plan.)
So maybe Wilson wasn't paranoid after all?
This is where it gets complicated. MI5 and others say Wright isn't a credible source. On a page of its website devoted to the allegations about Wilson, MI5 describes Wright's allegations about an anti-Wilson conspiracy within the service as "discredited". In Spycatcher, Wright claimed 30 MI5 officers had been part of the plot. Then, when questioned on Panorama, he revised that number down to eight or nine - and admitted that only one other officer was seriously committed to overthrowing Wilson. That part of the book was "unreliable", he said.
On the other hand, the chief of MI5 himself, when summoned by Wilson to Downing Street in 1975, admitted there had been a "small group of disaffected members" of the service who believed in the existence of a Communist cell in No. 10, according to a biography of Wilson by the historian Ben Pimlott. He assured Wilson this group was now under control.
It seems this didn't put Wilson's suspicions to rest…
No. And to be honest he wasn't the only one who felt uneasy. The writer Francis Wheen has described the period as "the golden age of British paranoia". There was a lot of talk of plots - and there were some actual plots.
In 1968 Daily Mirror owner Cecil King called a meeting of establishment luminaries, in which he called for the elected government to be replaced by an administration led by the Queen's cousin, Lord Mountbatten. But Mountbatten, who was present, refused, and the conspiracy went nowhere.
In the early 1970s, a number of right-wing ex-military figures, angry about trade union militancy, began building "civil defence" groups, which it was feared were effectively private armies. In a 2006 BBC documentary, former Army and security officials talked cheerfully about having urged a military takeover.
Baroness Falkender, Wilson's most trusted aide, said she and the prime minister had both believed that a 1974 Army training exercise at Heathrow Airport was in reality either a show of strength or a training run for a coup. Wilson also thought MI5 was planting damaging stories about him in the press - a claim which Wright said was correct.
Was there ever an investigation?
Yes, two. A 1987 inquiry concluded the allegations of a security service plot against Wilson were untrue. However, an inquiry by cabinet secretary Lord Hunt in 1996 concluded that "a few, a very few, malcontents in MI5" had "spread damaging malicious stories".
Prof Christopher Andrew's 2009 official history of MI5 confirmed that the service had opened a file on Wilson in 1947, under the code name "Worthington", after a Communist civil servant spoke approvingly of him. Andrew concluded there had been no MI5 conspiracy and described Wilson as paranoid. However, in his preface, he said there had been "one significant excision" from the book. It was later reported that this was a claim - suppressed by Whitehall on "public interest" grounds - that Downing Street was bugged from 1963 until 1977.
(Numerous sources recall Wilson telling them during his final spell in No 10 that the building was bugged.)
OK, you're right, it is complicated…
There is a lot that is still unclear, and historians are still arguing about it. David Leigh's 1988 book, The Wilson Plot, sets out the case for a conspiracy. Pimlott, Wilson's biographer, thought something murky was afoot, at the very least, as does the historian, Dominic Sandbrook.
Lomas suspects the truth lies somewhere in the middle - while the plot within MI5 may have been limited to "Peter Wright and a mate", there was undoubtedly a wider right-wing milieu in the 1970s that sought to bring down Wilson, he says.
"If you want to believe there was a Wilson plot, there's plenty of evidence there to support those allegations. If you're on the opposite side, that says this is a figment of the imagination, it never happened, there's evidence to support that argument as well," he says.
"That's one of the wonderful things about the Wilson plot. It's one of those whodunnits where there's no right or wrong - it depends on what you want to believe."
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