Building firm Skanska used an illegal blacklist of construction workers to vet employees for a history of violence and drug or alcohol abuse, an internal investigation has revealed.

Harvey Francis, executive vice-president for HR, told PM that it had subscribed to the list, which contained confidential details of 3,213 construction workers, “to ensure the safety of people working on our sites” – not to blacklist people on the grounds of trade union membership as reported in the press.