Eight of the U.K.’s largest construction companies said Oct. 10 that they would compensate construction industry workers who were damaged by an unlawful “blacklist” that allegedly operated since the mid-1990s and included more than 3,200 names.

Workers were added to the list for reasons that included health and safety issues, employment history, trade union activity and personal relationships, says Justin Bowden, national officer of GMB, a leading U.K. construction trade union, and media reports.

Bowden, who adds that some workers were listed for being troublesome, says the total value of compensation claims could run into “hundreds of millions of pounds.”

The contractors that have agreed to the compensation settlement are: Balfour Beatty plc., Carillion plc, Costain Group plc, Kier Group plc., Laing O’Rourke Ltd., Sir Robert McAlpine Ltd., Skanska U.K. plc. and VINCI plc.

In a joint statement, the companies apologize for their involvement with the blacklist operator, a privately-owned firm known as The Consulting Association, and “the impact that its database may have had on any individual construction worker.”

They also call on other users of the list to participate in the compensation scheme.

Details on 3,213 workers were kept on a register used by more than 40 firms, according to an 2009 investigation by the Information Commissioner's Office (ICO), the U.K.’s data protection regulator.

The Consulting Association (TCA), which is now defunct, charged subscribing contractors an annual fee of $4,800, according to the ICO.

“We are talking about 3,213 people who were, in some cases, denied employment for 15 years,” adds Bowden. Only about 20% of the affected workers have so far been traced.

TCA owner Ian Kerr was fined nearly $8,000 in 2009 for breaking the data protection law. A month later, the ICO ordered 14 contractors to stop using the firm’s data.

Allegations of blacklisting on London’s $24-billion Crossrail project were withdrawn last month after a year-long campaign by the UNITE union.

The dispute was triggered by a subcontractor's dismissal of 28 electricians after its work concluded for the BFK joint venture, whichi is owned by Spain's Ferrovial Agroman S.A. partnered with the U.K.'s BAM Nutall Ltd. and Kier Construction Ltd.

The dispute ended last month when the union agreed that no blacklisting had occurred. BFK conceded that the subcontract's completion “could have been handled better."