As part of the overall settlement, which is subject to court approval, 53 blacklisted workers will receive over £1.9m in compensation.

The defendants – Balfour Beatty, Costain, Kier, Laing O’Rourke, Sir Robert McAlpine, Skanska UK and VINCI –  have also agreed to pay Unite’s legal fees.

The contractors have also agreed to place £230,000 into a training fund which will be administered by Unite for all victims of blacklisting who have brought proceedings.

They have also agreed to work at national, regional and site level to ensure that the modern UK construction sector provides the highest standards of employment and HR practice.

The latest court case follows the 2016 court action which resulted in Unite securing £19.34m for 412 blacklisted workers.

Unite assistant general secretary Howard Beckett said “This is a historic agreement which provides some degree of justice to a further group of construction workers who had their working lives needlessly ruined by blacklisting construction companies.

“The creation of a training fund controlled by Unite is a huge breakthrough, and is to be welcomed, as it will allow the union to assist victims of blacklisting return to employment.”

“The blacklisting construction companies promised public statement is welcome about their future good behaviour and a new relationship with unions, but these words must be followed up by genuine actions.

“If they are serious, they must provide genuine unrestricted access to their sites and workforces, end the practice of moving union activists from one job to another to disrupt union organisation, end the reliance on agency labour and end the scandal of bogus self-employment.”