At least 10 workers from Northampton and another four from across the county were placed on an illegal blacklist which looked at the backgrounds of thousands of construction workers before they were given jobs, it has been claimed.
The figures have been released as part of a bid to uncover the true scale of the of people hit by secret blacklists that aimed to stop union members getting jobs.
GMB, the union for construction workers, has revealed a detailed breakdown of the number of workers put on blacklists across the East Midlands, where it says it is known that at least 60 workers on the construction industry were hit.
The union says less than 10 per cent of them know they are on the list and none has been compensated.
The blacklist first came to light in 2009, when the Information Commissioners Office (ICO) seized a Consulting Association database of 3,213 construction workers.
The GMB union claims the list was used by 44 companies to vet new recruits and keep out trade union and health and safety activists.
The ICO allegedly never contacted anyone on the list to let them know they were blacklisted.
Three years later, by autumn 2012, just 194 of the 3,213 people on the blacklist knew they were on the list as these had contacted the ICO directly.
GMB is to step up a campaign to get each and every GMB members blacklisted proper compensation.
Paul Kenny, GMB General Secretary, said: “People have been deprived of an honest living through these illegal tactics which has blighted their families’ lives.
“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.”