The Royle Family actor Ricky Tomlinson is among the campaigners urging the government to release documents relating to the "Shrewsbury 24" case.
Today he accused ministers of telling "bare-faced lies" in refusing to release all the documents because of "national security", which he believes proves the arrests were politically motivated.
Tomlinson was one of six building workers imprisoned in 1973 after being arrested for picketing following a national strike.
Steve Murphy, general secretary of the building workers' union Ucatt, is supporting the campaigners' cause.
He said: "The news that the government papers will not be published for at least another 10 years is appalling.
"What they are hiding is a massive government conspiracy and shows that the home secretary of the day connived with the police and security forces at the behest of construction companies to make an example of ordinary workers."
Using Jim Royle's catchphrase, he added: "National security, my arse."
More top news
Jamie Oliver turned down the offer of playing a hobbit in the movie adaptation of the book by JRR Tolkien, the TV chef has revealed.
Children are being put at risk as 11% of posts for permanent children's social workers remain unfilled, experts have warned.
A Network Rail boss who presided over the Christmas trains chaos will not receive a bonus of more than £300,000 when he leaves in February