'A tightly-knit group of politically motivated men' - MI5 and the CPGB
Cover page of newly released MI5 file KV3-448 (UK National Archives).
Last week’s MI5 document dump may have fuelled the British press’s traditional obsession with the exploits of Kim Philby, Anthony Blunt and their fellows, but not all the interesting material in the release concerned the Cambridge Spies.
Over at Declassified UK, veteran intelligence journalist Richard Norton-Taylor has unearthed documents which shed new light on the complex relationship between the Security Service, the Communist Party of Great Britain and the British labour movement.
MI5 spies were regularly summoned to 10 Downing Street for clandestine meetings with Labour prime minister Harold Wilson to share material on striking seamen, hitherto top secret files from 1966 reveal.
The full extent of his close relationship with senior MI5 officers is contained in scores of documents declassified on Tuesday at the National Archives in Kew.1
The broad outlines of this story have long been known. Wilson blamed the Communist Party for the strike in a famous statement to the House of Commons.
It is difficult for us to appreciate the pressures which are being put on men I know to be realistic and reasonable, not only in their executive capacity but in the highly organised strike committees in the individual ports, by this tightly knit group of politically motivated men who, as the last General Election showed, utterly failed to secure acceptance of their views by the British electorate, but who are now determined to exercise backstage pressures, forcing great hardship on the members of the union and their families, and endangering the security of the industry and the economic welfare of the nation.2
As long ago as 1991, Wilson biographers Stephen Dorril and Robin Ramsay reported the role of MI5 officer Dick Thistlethwaite, whose service provided the Prime Minister with comprehensive intelligence on the strike, based on bugging and infiltration.3
The new files confirm much of this picture and provide a remark insight into how the Communist party’s involvement was regarded by MI5 director-general Martin Furnival-Jones.
….the MI5 files say that while CP members had been influential in some local strike committees, they were “numerically weak” in the NUS and their role was diminishing.
Perversely, that caused concern to MI5. On 17 June 1966, Furnival-Jones reported that “as the [Communist] party looked as though it was going to withdraw from the strike, our sources of information would dry up”.4
On the face of it, this was welcome news. The Communist withdrawal should have meant that the strike was no longer a subversive threat, but simply a domestic industrial dispute. Furnival-Jones’ words suggest that, in reality, the Party provide a useful pretext to collect intelligence on the National Union of Seamen.
Some on the British left have long suspected that MI5 pulled its punches in relation to the Communist Party for just this reason.
In his controversial memoir Spycatcher, MI5 officer Peter Wright revealed that the service was aware that the party was receiving ‘Moscow gold’ - subsidies from Soviet officials.5 This is one aspect of Wright’s story that was later confirmed by Christopher Andrew’s authorised MI5 history.6
In The Clandestine Caucus, Robin Ramsay argued that MI5 could have destroyed the Communist Party, but chose not to.
I do not want to argue that MI5 were running the CPGB. But it did allow the CPGB to run. Had the existence of the ‘Moscow gold’ been revealed in 1957 or 8, coming after the Soviet invasion of Hungary, the CPGB would have been terminally damaged. But for MI5 the ‘communist threat’ - and the link to the Soviet Union - was simply too useful a stick with which to beat the wider labour movement and Labour Party to be surrendered.7
There are other explanations for MI5’s approach. Given the extent of the service’s coverage of the CPGB, there was an obvious counterintelligence case for using it as a honeypot to keep an eye on the Soviets.
Yet Furnival-Jones’ comments suggest that it could also be a honeypot for domestic dissent, and the 1966 strike was probably not the last occasion on which this was true.
MI5 whistleblower Cathy Massiter revealed in the 1980s that she had been tasked to find a suitable communist to justify surveillance of the Campaign for Nuclear Disarmament. The instruction came shortly ahead of the 1983 general election, in which nuclear disarmament was a key dividing line between the parties.8
MI5’s counter-subversion work had been downgraded by the 1990s.9 This no doubt reflected the end of the Cold War, but also came after a major defeat for the unions in the 1984-85 Miners’ Strike. Changing domestic considerations cannot therefore be ruled out as a factor.
The War on Terror era saw the old concept of counter-subversion revived under the new name of counter-extremism. In recent years, the revival of great power competition has given the original term renewed currency.
The latest MI5 releases give us a new insight into a key episode in the story of British counter-subversion, but the files peter out in the 1970s. Some of the later chapters in the story are currently being chronicled by the Undercover Policing Inquiry. So far, the results suggest that while the CPGB may have gone the way of the Soviet Union, any shortage of pretexts for political surveillance was strictly temporary.
Richard Norton-Taylor, Labour leader praised MI5 for spying on trade union, Declassified UK, 14 January 2025.
Harold Wilson, Seamen’s Strike, House of Commons Hansard, 20 June 1966.
Stephen Dorril and Robin Ramsay, Smear! Wilson and the Secret State, Fourth Estate Limited, 1991, p.130-131.
Richard Norton-Taylor, Labour leader praised MI5 for spying on trade union, Declassified UK, 14 January 2025.
Peter Wright, Spycatcher: The Candid Autobiography of a Senior Intelligence Officer, Viking, 1987, p.175.
Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.409.
Robin Ramsay, The Clandestine Caucus: Anti-socialist campaigns and operations in the British Labour movement since 1945, Lobster, 1996, (updated 2023), p.71.
Stephen Dorril, The Silent Conspiracy: Inside the Intelligence Services in the 1990s, Mandarin, 1994, p.26.
Christopher Andrew, Defence of the Realm, The Authorized History of MI5, Allen Lane, 2009, p.780. Andrew’s organisational charts show that MI5’s countersubversion wing, F Branch, was merged first with C Branch (protective security) in 1988, and then with K Branch (counterintelligence) to form a new D Branch by 1994.
The MI5 bugs that recorded conversations at King Street were invaluable for cross-referencing the movements and opinions of hundreds (if not thousands) of unwary visitors to the CPGB HQ.