Campaigners are trying to quash convictions against the so-called Shrewsbury 24, who were arrested five months after the 1972 building workers' strike and charged under the 1875 Conspiracy Act, with six sent to prison.
A 100,000-signature petition has been delivered to the Government with campaigners claiming the charges were politically motivated with government interference in the prosecutions.
Labour MP Dave Anderson has secured a backbench debate on the case, which was being held in the Commons today. Royle Family actor Ricky Tomlinson, one of those jailed, said ahead of the debate: "Unless there is action now the ban on releasing these papers won't be reviewed until 2021."
Unite general secretary Len McCluskey said: "It is time to end this four-year conspiracy of silence and release all the government documents relating to the Shrewsbury 24."
The group wants all documents rel-ating to the case to be released, claiming they would prove a "massive miscarriage of justice".