The surveillance and blacklisting of thousands of workers, including some suspected by construction companies of being left-wing troublemakers, should be investigated by the privacy watchdog, it was urged last night.
More than 40 major firms referred to the secret database, which listed thousands of people's details, including their involvement in union activity, before hiring staff.
Workers who were on the list allege they were deprived of their livelihoods, with supporters claiming their human rights have been breached.
Liberty has written to the Information Commissioner, Sir Christopher Graham, accusing him of inaction over the privacy scandal.
The database was seized three years ago and Ian Kerr, who had operated it, was fined £5,000.
An official from the Information Commissioner's Office told the industrial tribunal of a person who had been blacklisted that he believed the information on the database could only have been supplied by the police or the security services.