Fifty thousand people must put pen to paper if the Shrewsbury show trials’ survivors are ever to see justice, campaigners have said.

Political prisoner turned sitcom star Ricky Tomlinson pointed to the exposé of the “disgraceful” Hillsborough cover-up as a sign that campaigns can work.

The former plasterer was one of 24 construction workers arrested and charged after they picketed Tory peer and construction magnate Sir Robert McAlpine’s building sites in 1972 — despite advice from the then-director of public prosecutions that there was not enough evidence to secure a conviction.

Campaigners have accused members of the Tory Heath government of engineering the trials to break the militant trade unions’ resolve.

Ministers have suppressed the records’ release ever since, and in 2011 the then justice secretary Ken Clarke extended the ban until 2021 — on grounds of national security.

Mr Tomlinson said yesterday the campaign’s paper petition now needed 100,000 signatures by October to demand that the government publicly debate the records’ release in the House of Commons.

The odds were stacked against them, he said.

But the families of those who died in the 1989 Hillsborough disaster had refused to give up and the latest exposés and public anger over the case had given him hope.

“The crying baby gets fed first, as you know.

“The Shrewsbury campaign, the Hillsborough justice campaign — heads have got to roll,” he said.

Shrewsbury researcher Eileen Turnbull agreed. “You don’t want to think about how awful that was.

“But what Hillsborough has done is opened the door so that people believe in what goes on and what the government withholds.

“Now people go: ‘We know it’s the government and we know they’ve held things back.’

“They were told (lies) by upstanding police — and not just police, the coroner — with orders from up the chain of command, and it went on and on.

“Who would believe that?” she said.

Petition forms can be downloaded from shrewsbury24campaign.org.uk