Hundreds of people from around the country joined a march through Shrewsbury last Saturday.
They demanded justice for the 24 building workers convicted in the town in 1973, after standing on a picket line.
Mike Abbott, national secretary for the Justice for the Shrewsbury Pickets campaign, said, “The workers were on strike over their demand for £1 an hour and better safety and working conditions.
“The strike was all over the country but the 24 were arrested in Flintshire and Mold in North Wales and tried in Shrewsbury Crown Court to set an example to the trade union movement.
“We’re going to do this every year until they are exonerated.”
Paul Brandon, chair of the Right to Work campaign, made a call to build for a massive show of defiance at the Tory party conference in Birmingham on 3 October.