Unions leaders want information chiefs to release the names of construction workers found on an industry blacklist dating back 30 years.
Some 98 workers from across the South West are on the blacklist, which unions claim deprived them of work although the individuals may not yet know it. Of that number, 19 were from Devon, three from Cornwall and three from Somerset.
Information contained on the blacklist included names, address, place of work, political affiliations – including communist – and trade union membership.
If individuals complained about health and safety on building sites they could also be blacklisted, according to unions.
The list came to light when in 2009, the Information Commissioners Office (ICO) seized a database from The Consulting Association (TCA) containing the names of 3,213 construction workers. Ian Kerr of TCA, who supplied the data, was later fined £5,000 for breaching the Data Protection Act – the TCA no longer exists and Mr Kerr has since died.
The GMB union, which represents construction workers, is fighting for compensations from construction companies who used the blacklist.
It wants the ICO to release the names in order for workers to come forward.
The ICO said the move would breach the Data Protection Act and is trying other methods to trace those on the blacklist.
Paul Kenny, GMB general secretary, said people had been deprived of an honest living through "illegal tactics" which have blighted their families' lives.
He said: "They have been the victims of injustice over many years by multi-national companies – now seeking to live off public sector contracts.
"Not a single company has yet been punished nor have any of them paid compensation.
"GMB priority now is to step up the campaign to get each and every GMB member blacklisted proper compensation.
"We are also still pushing the ICO for a proactive action to inform all construction workers on the list that they are on the blacklist.
"Blacklisting was not something isolated or rare."
David Smith, deputy commissioner and director of Data Protection at the ICO, said they had quickly established a fast-track system for people to find out if they're included on the blacklist.
He said "So far we've taken calls from 2,641 people, of which we found 218 who were listed.
"On top of that, we've also been working with construction trade unions to try to proactively reach more individuals whose information is included within the Consulting Association files.
"We are also looking at how we could overcome the challenges of writing to people on the blacklist.
"This is impossible in many cases, as a lot of the entries in the database are incomplete, inaccurate or extremely dated.
"What's more, as the regulator of the Data Protection Act, we know all too well the problems of letters being sent to the wrong address.
"That means we need to be sure that any correspondence hinting at inclusion on the blacklist goes to an address that we can be reasonably confident is up to date and accurate.
"The difficulty is that the construction blacklist is very dated.
"When we seized the database in 2009, many of the files were already out of date, with some of them more than 20 years old.
"We're close to finalising arrangements with a commercial service that can assist us with confirming some of the addresses are up to date, and we hope that this will be done shortly."