Construction workers from South Yorkshire and Derbyshire are among dozens of builders taking High Court action against employers who discriminated against them via a secret blacklist.
Law firm Leigh Day has resumed action seeking compensation for workers - including 56 workers from Rotherham and a further 16 from Derbyshire - in the High Court in London today
After years of denial, employers have admitted they used an illegal blacklist to deny workers who raised health and safety complaints - or were affiliated with unions - the work they deserved.
It finally came to light in 2009 when the Information Commissioners Office seized a Consulting Association database which featured the names of more than 3,200 construction workers and environmental activists - used by 44 companies to vet new recruits.
So far, just 1,724 construction workers from across the country know that their names were on blacklist.
Several hundred of these are covered by claims in the High Court action.
The GMB, the construction workers union, said work to trace the other remaining 1,489 workers is continuing.