Last month Lee Harper became the second construction boss to be sent to jail for a death on site. The managing director of Harper Building Contractors of Cannock pleaded guilty to manslaughter after an employee stepped backwards onto a rooflight and fell to his death.

A judge at Manchester Crown Court sentenced Harper to 16 months after the court heard that no safe systems of work had been prepared and there were no safety precautions in place. Daryl Arnold, who had never worked on a roof before, fell 6.75m in June 2003.

In May 2002 another construction boss Brian Dean was sentenced to 18 months after two workers died while demolishing a chimney, but his conviction of manslaughter was overturned at appeal.

Harper pleaded guilty to manslaughter. No safety precautions had been in place