Trade unionists have revealed that 28 workers in Tayside were blacklisted by construction firms.
The details came to light following a hearing at the High Court in England, where 12 companies, including V&A contractors BAM Construction, were ordered to reveal how workers were blacklisted and disclose documents.
Blacklisting came under the microscope in 2009 when the Information Commissioners Office seized a Consulting Association database of 3,213 construction workers and environmental activists.
It was used by 44 companies to vet new recruits and keep out of employment trade union and health and safety activists.
In total, 21 workers in Dundee were affected.
Dundee man Steuart Merchant, 69, is one of 571 workers taking legal action.
He spent the last 13 years of his career doing shop-fits because he was blacklisted but has never been told why he was given the black mark.
Mr Merchant added: “This is brilliant news. It means the companies will now have to show where they got their information and how they used it.
“It is common knowledge that these companies got their information from other companies.
“I would hope that companies will now hold their hands up, admit that they were part of an illegal operation stopping genuine people from getting employment, say they disagree with that totally and reimburse the people affected.”