SITE DEATH PROSECUTIONS 'PLUMMET'

Ucatt said that in the six years to 2004, prosecutions "plummeted" from 42% to 11%, with some cases taking three years to come to trial.

Officials said the failure to prosecute had a "devastating" impact on bereaved families who often felt betrayed by the system.

According to the union, conviction rates are far below Health and Safety Executive figures.

Alan Ritchie, general secretary of Ucatt, said: "The failure of the HSE to prosecute companies who kill their workers is profoundly shocking."

The report also found huge regional differences in the likelihood of a company being prosecuted when a building worker is killed.

It is three times more likely that a conviction will occur in the South West than in the East Midlands, it was claimed.