Trade unionists demanded a "Leveson-style" inquiry today into the blacklisting of thousands of construction workers.
Unite said the issue was as scandalous as the media's phone-hacking and it wants a similar response.
MPs are to debate blacklisting tomorrow.
Britain's data watchdog exposed the widespread use of secret blacklists in the building trade in 2009 when its officers raided the offices of the Consulting Association.
More than 40 of Britain's largest construction firms were shown to have used a blacklist of 3,213 workers.
Unite said: "After years of denials, firms which built the Olympic Park have finally admitted that they checked names of prospective workers with the illegal Consulting Association blacklist.
"Many of the workers still have no idea that they were included on the blacklist."
Crossrail industrial relations chief Ron Barron was sacked from the London transport project when his involvement in blacklisting was revealed.
Former Consulting Association chairman Ian Kerr admitted having discussions with Crossrail.
Crossrail union rep Frank Morris and 27 other workers employed by a subcontractor were sacked.
Mr Morris believes BAM Nuttall Ltd, Ferrovial Agroman and Kier Construction Ltd, who won £700m in Crossrail contacts, were involved.
Both BAM and Kier subscribed to the Consulting Association's blacklist.
Mr Morris believes he was blacklisted for raising health and safety concerns at the London Olympic site.
Unite believes Crossrail has failed to investigate evidence of blacklisting on the project and wants Transport for London to investigate.
Thousands were denied jobs after raising health and safety concerns or for their trade union activities.
"Many of the workers still have no idea that they were included on the blacklist which was uncovered in the raid by the Information Commissioner's Office in 2009," Unite said.
Today's Commons debate has been instigated by shadow business secretary Chuka Umunna.
He wants the Information Commissioner to inform the victims that they were blacklisted so they can seek compensation.
Unite general secretary Len McCluskey said: "This is a scandal on the scale of phone hacking, except it is the lives of thousands of ordinary construction workers which have been ruined.
"There should be a full and proper inquiry. It is time for justice."
If you appreciated this article then please consider donating to the Morning Star's Fighting Fund to ensure we can keep developing your paper.
George Osborne's advice from the International Monetary Fund is like the curate's egg - good in parts.
George Tapp suffered horrific injuries when he was run down last week at a demo against blacklisting in construction. He tells the Star why he's as determined as ever to carry on struggling for justice
The government wants to ramp up Western involvement in the Syrian conflict but the cost will be more violence and instability in the region