Ricky Tomlinson's plea for justice over Shrewsbury 24

The Royle Family actor was close to tears as he recalled serving 16 months in jail for charges he insisted were politically motivated.

He told a fringe meeting at the Labour conference in Manchester yesterday that even after years of campaigning he still had 'fire' inside him to seek justice.

His son and grand-daughters had faced taunts because of his conviction, he said, which was one of the reasons he continued to press for the convictions to be quashed.

The 24 building workers were arrested and charged under the 1875 Conspiracy Act, with six sent to prison.

Mr Tomlinson said the picketing in Shrewsbury in 1972 had been entirely peaceful, but the group of men were arrested five months later.

Jurors at their trial were wrongly told by a court usher that the men would only be fined £50, but prison sentences were handed down, he claimed.

Mr Tomlinson served 16 months of a two-year sentence for conspiracy to intimidate.

Terry Renshaw, one of the pickets, said he was confident the Criminal Cases Review Commission would overturn the charges.

He said: "There was obviously political interference from the Conservative Party in bringing the prosecutions, but Cabinet papers from the day which would prove our case will not be released because of so-called security reasons.

"The Government deny it was a political trial but they cite security in refusing to release all the papers – it just doesn't add up."

Mr Renshaw, at 64 is the youngest of the 24. Four of pickets have died.