The Information Commissioner’s Office is investigating the leak of confidential files naming blacklisted construction workers, writes Andrew Hankinson.

The files, which contain details of the trade union activity of 3,213 construction workers, were taken out of circulation in March 2009 when the ICO seized them from the Consulting Association.

The CA had been selling them to construction firms concerned about employing union activists. The CA was later closed down and in July last year its owner, Ian Kerr, was fined £5,000 for data protection breaches.

One worker said his file was posted anonymously to his home address and that he was aware of at least eight files in circulation.

“If these bastards send it round again they can stop me working again,” he said. “I never broke any law or turned up late or drunk. All I did was complain about health and safety.”

The ICO said it was aware of “two unredacted blacklisting documents” in circulation and was monitoring events closely.

David Clancy, investigations manager at the ICO, added: “We will review any new evidence that is brought to us regarding the source of the leak, establish how it occurred and consider what remedial action needs to be taken to prevent this happening again.”

The worker said he believed the files had been circulated as a form of threat by a firm that had been allowed to photocopy them at the ICO’s office, in order to defend itself during an unfair dismissal hearing. The ICO said it was “satisfied” the files were not leaked from its offices.

It added that Kerr has told the organisation he had securely destroyed any record of the files he had found subsequent to the ICO’s seizure.

Firms that paid to use CA’s blacklists over several decades include Balfour Beatty, Bam Nuttall, Costain, Kier, Laing O’Rourke, Shepherd, Sir Robert McAlpine, Skanska and
Willmott Dixon.