The TUC is calling on the Government to change the law so that all accidents involving employees killed while driving as part of their work are investigated as workplace accidents.

It believes the move would be a start in tackling some of the causes behind why about 1,000 employees are fatally injured every year on the roads.

It hopes to see the Health and Safety Executive investigating every accident on the roads involving people working.

The TUC says that in addition to the high number of worker deaths, there are about 12,000 serious injuries to driving workers, and 70,000 lesser injuries every year.

At a seminar in Birmingham tomorrow, TUC health and safety officer Tom Mellish will set out the TUC's case, arguing that because the deaths of employees killed while working on the roads are only investigated by the police, the causes behind the accidents almost never come to light.

The TUC wants to see the law changed to force employers to carry out risk assessments for their driving workers, and for bosses to be as responsible for the safety of their drivers as they are for their non-mobile staff.

TUC general secretary John Monks said: "Workers who drive for a living are more than three times more likely to be killed at work than any other worker.

"Aside from the pain and suffering caused to them and their families, this tragic toll is a massive £3.7bn annual cost to society and a sky high £2.7bn to employers.

"It is a scandal that the death of a driver killed while working is not investigated in the way it would if they had been killed on the factory floor."