On behalf of 1,700 inspectors, scientists and other professionals in HSE, Prospect says it supports the call from survivors, and the families of those killed and injured, for a full public inquiry as the narrow remit of the initial inspection failed to answer a number of issues or provide lessons to avoid future tragedies.

Michael Macdonald, Prospect Negotiations Officer, said: "The prosecution of ICL Plastics Ltd and ICL Tech Ltd focussed on the narrow range of issues covered by the law but this inevitably left many broader policy questions unanswered.

"Prospect is also disappointed by rumours that appear to cast blame on individual inspectors. While the criminal investigation and subsequent court hearing were ongoing, it was not possible for our members who have been closely involved in the case to respond."

A public inquiry, said Macdonald, should focus on the key issues affecting the performance of the HSE in Scotland and across Great Britain, to inform any changes needed to ensure the best health and safety protection for workers.

"In particular the debate over Stockline should not scapegoat individuals constrained by public policy but should concentrate on improving the effectiveness of the HSE," he said. "The government needs to accept responsibility for placing a greater focus on funding than effectiveness - the victims of Stockline deserve nothing less."

HSE has been forced to cut back on staff numbers and training, close offices and prioritise work on risks causing the greatest numbers of injuries in the workplace as it chases reductions outlined by Public Service Agreement targets. These priorities are slips and trips, workplace transport, falls from height and musculoskeletal disorders.

Since 2003, HSE inspectors are under instructions to look just at these issues during inspections. Unless "matters of evident concern" are raised they cannot use their experience and discretion to look into other risks such as fire and explosion risks, structural safety and dangerous machinery.

Neil Hope-Collins, Prospect HSE Branch Chair said: "Our members are committed to serving the public of Scotland and trying to prevent workplace injury and ill-health but are just too stretched to do all the work they feel is necessary. We need to let skilled professional inspectors use their judgement to tackle all serious risks and turn poor workplaces into decent ones."