Union official Bob Blackman has urged council to “think carefully” before removing from their tender lists companies that are being investigated by the OFT for price-rigging .

Blackman, who is national construction officer for the T&G section of the Unite, said: “A number of the firms that the OFT alleges are involved in price-rigging also have multimillion maintenance contracts with local authorities under which they took over thousands of former local government direct labour staff.

“It might be right that these firms are removed from local authority contracts if they are found to have engaged in anti-competitive practices, but there is likely to be a knock-on effect that will affect many thousands of jobs.”