Legal action threatened over 3000-strong bank of names and national insurance numbers

A blacklist of 3200 m&e workers used by several major contractors has been uncovered, according to union sources speaking to Building magazine.

Ian Kerr, a private consultant, is understood to have had his Worcestershire office raided and computer and files seized by Data Protection Services. Kerr is understood to be a retired special branches officer.

In addition to the workers' names and national insurance numbers, 40 invoices were discovered from major construction firms who are alleged to have used Kerr's services, reportedly to check up on potential employees.

The blacklist relates back to projects in the m&e sector which were hit by industrial disputes during the 1990s and early 2000s, including the Royal Opera House, Pfizer and the Jubilee Line extension. It contains the names of workers involved in trade union disputes and employment tribunals.

The existence of an m&e blacklist was first uncovered in 2006. Allegations were posted on an internet blog by Alan Wainwright, a former regional resources manager at an m&e contracting firm. In the blog, Wainwright stated: "I have reasonable grounds to believe that certain UK construction companies and their m&e subsidiaries operate a blacklisting procedure to ensure certain electrical operatives do not gain employment.”