If construction firms continue to use blacklist they could be found guilty of breaching the Data Protection Act

Construction firms who paid the Consulting Association to vet potential site workers could face prosecution by the Information Commissioner’s Office if they fail to clean up their act.

If found guilty of breaching the Data Protection Act firms can face unlimited fines. The news follows an investigation by the Information Commissioner’s Office which this week said it was prosecuting the director of the Consulting Association over a list of 3,213 workers which 40 firms had paid to subscribe to in a bid to vet workers.

Listed firms include Balfour Beatty, Amec, Costain, Morgan Ashurst, Sir Robert McAlpine and Taylor Woodrow.

A spokeswoman for the ICO said the body would be sending out enforcement notices telling firms to stop using the list. If the firms continued using information from the list, they spokeswoman said they would prosecute them.

The spokeswoman said: “We are expecting to serve a number of enforcement notices, and we are continuning to look at the evidence to determine our exact next steps.”

The spokeswoman said the ICO could not rule out the possibility of prosecutions on past actions, although it was currently expecting only to issue enforcement notices. She was unable to say when the notices would be served.

Firms are liable for unlimited fines if prosecuted successfully for breaching the Data Protection Act in a Crown Court.