The revelations that the Heath government in 1974 influenced the content and timing of an anti-union TV documentary – and may have influenced a jury – will not exactly surprise union veterans from that time. The “Shrewsbury trials” became infamous for the use of conspiracy charges against trade union militants. Des Warren, now deceased, and Ricky Tomlinson – still very much alive as a renowned actor – were jailed for conspiracy to intimidate, unlawful assembly and affray, following altercations at a construction site in Shrewsbury two years before.

Warren was sentenced to three years, Tomlinson two. A total of 24 men were put on trial. As picketing was not illegal, the use of “conspiracy to intimidate” was seen at the time as an attempt to shackle militant, rank-and-file trade unionism. As conspiracy was an offence under common law, its acknowledged use in British politics had been, for centuries, to suppress rebellions, not ordinary crimes.

Andy Burnham, the shadow home secretary, will this week release documents showing that prime minister Edward Heath’s cabinet, and the security services, influenced an ITV documentary called Red Under the Bed featuring the defendants at the trial, which was broadcast on the day the jury retired to deliver its verdict (the judge dismissed the defence’s argument that the film was in contempt). “We want more of this,” says Heath in a Downing Street note. Further evidence relating to the case remains locked in the National Archives, suppressed on grounds of national security.

Yes, children: the 1970s were a very strange time. And though the injustices of the era have begun to be explored in TV dramas and in the serial trials of paedophile celebrities, the Shrewsbury case goes to the heart of why, even now, there are still no-entry signs on some of the decade’s dark passageways.

When we see the 1970s reconstructed now, in popular culture, the most commonly omitted fact is the biggest: between 1972 and 1974, Britain could easily have seen either a workers’ revolution or a military coup.

The scale of workplace radicalisation is, even now, undocumented. If you mixed, as I did in the early 1980s, with shop stewards who had virtually controlled places including the Ford plants at Halewood, Dagenham and Langley 10 years previously, you were meeting people viscerally at odds with the economic system. They wore their hair long, they raced each other in souped-up Capris and Escorts late at night; but they would bundle themselves into the same cars to drive halfway across Britain to join a picket line or kick some fascists’ heads in.

The sociology of workplace revolt was terrifying for the authorities because it defied the one institution that was supposed to keep it in check: the trade unions. Arthur Scargill, eventually, got to lead the NUM. But, at the time he closed down the Saltley Gate coke works outside Birmingham, he was still a rebel within the union. Most unions were controlled by ultra-moderates, whose political machine within the unions closely matched the objectives of the cold war state: to suppress radicalism.

But it didn’t work. The generation whose sexual freedom, individualism and rising literacy had caused sociologists to write them off as any kind of proletariat turned out to be the most militant of all.

In the summer of 1972, when UK building contractors imposed what we would now call “bogus self-employment” on their workforce, a 12-week builders’ strike took place, in which the union rank and file made widespread use of flying pickets. They would arrive unannounced at a working site and drag the strikebreakers off the job. Sometimes it was not pretty, but it was mild compared with, for example, the mob violence that football clubs tolerated.

Striking building workers in September 1972. Photograph: Evening Standard/Getty Images

In October 1972, the employers compiled a dossier of evidence of intimidation in the strike and handed it to Conservative home secretary Robert Carr. Construction boss Robert McAlpine wrote to the Metropolitan police commissioner demanding “enforcement of the law by the police”. Carr then ordered a team of detectives to build a conspiracy case against the union militants.

They were brought to trial first at Mold, in two hearings, both of which effectively collapsed with minor or no convictions. This, according to campaigners, was partly due to the right of defendants to challenge the membership of juries at the time. After those trials the conservative Lord Chancellor, Hailsham, abolished the right of defence lawyers to vet juries, and the stage was set for Shrewsbury.

Both Warren and Tomlinson were, in their own ways, emblematic members of that generation. Warren was a communist who became a Trotskyist on release from prison. Tomlinson had briefly been sympathetic to the National Front but moved to the left, becoming associated with a series of political projects to the left of Labour. Warren, at his trial, made a pre-sentence speech claiming that “the real conspiracy was between the home secretary, the employers and the police”. By today’s standards, that sounds accurate. A politicised police investigation, fuelled by pressure and intelligence from business owners engaged for decades in the illegal blacklisting of militants, ordered by a home secretary and amplified by willing journalists.

The checks and balances inside Whitehall, the police and the prosecution service would today make such a coordinated and politicised act very difficult to do unless you invoked national security procedures. The use of conspiracy charges under common law was recognised as archaic and unjust, and replaced with a criminal conspiracy law in 1977.

The Shrewsbury 24 campaign is calling for the convictions to be overturned by the Criminal Cases Review Commission. But maybe we need something bigger. So deep was the intrigue of the 1970s, so heavily overlapped were the intelligence services with normal policing and abnormal politics, that we might need something like a “truth and reconciliation” commission to sort it out.

From numerous paedophile ring allegations, to the Birmingham Six, to Bloody Sunday, to allegations of military coup plots contained in the Harold Wilson tapes, the decade’s lies keep coming back to haunt us. We’ll need more of the truth before we can put them to rest for good.

This article was amended on 7 December 2015. It originally referred to Ford plants at Longbridge, Dagenham and Langley in the 1970s. There was no Ford plant at Longbridge; but there was one at Halewood. This has been corrected.



Paul Mason is economics editor of Channel 4 News. @paulmasonnews