Unions condemned the “cynical” launching of an industry-controlled compensation scheme for blacklisted construction workers yesterday ahead of an imminent High Court hearing.

In 2009 the Information Commissioner’s Office raided the offices of the Consulting Association, seizing a database of 3,213 names which 44 firms had been using to keep trade unionists and green activists off their sites.

It took four years of campaigning before just eight of those companies — Balfour Beatty, Carillion, Costain, Kier, Laing O’Rourke, Sir Robert McAlpine, Skanska UK and VINCI PLC — announced the Construction Workers Compensation Scheme (TCWCS) last October, to compensate the victims they blacklisted.

But as the TCWCS was launched yesterday unions poured scorn on it, warning that participation could see workers receiving as little as £4,000 in compensation and pointing out that under the rules only a handful of workers would even qualify.

And crucially, if a worker agrees to enter the compensation scheme they will be effectively barred from taking further legal action.

Unions accused participating firms of ignoring a statement by the Scottish affairs select committee in March that it was unacceptable for companies involved in blacklisting to launch a unilateral scheme.

Construction union Ucatt general secretary Steve Murphy said: “This is a deeply cynical attempt by the blacklisting companies to try to prevent workers, who have had their lives ruined, getting justice.

“Blacklisting companies have ignored MPs and ignored blacklisted workers in launching this scheme. This is simply a cynical gimmick before the High Court case begins next week.”

The unions also pointed out that no agreement had been reached with them or any other representatives of blacklisted workers prior to the scheme being launched.

GMB national officer Justin Bowden said: “To try and present such a grossly inadequate sum of money as meaningful compensation for the devastating damage inflicted on the livelihoods and families of the thousands of people they blacklisted, and for the gross invasion of privacy they committed, suggests they are sorry only that they got caught.

“These construction companies lied and spied and this is the paltry price they place on 15 years of blacklisting. Their cut-price compensation offer is not an act of contrition, it is a PR stunt. Legally-represented workers are likely to get a much better settlement through the courts.”

The GMB said that the eight firms comprising the TCWCS had a combined turnover of over £34 billion and pre-tax profits of £1.04bn.

“They can afford properly to own up, clean up and pay up,” Mr Bowden said.

Unite assistant general secretary Gail Cartmail suggested that if the blacklisters truly wanted to compensate blacklisted workers, they should give them their jobs back.

The High Court case is due to begin on Thursday July 10 in London.