The Institute of Occupational Safety and Health (IOSH), which commissioned the research based in the construction industry, found there were fewer accidents when health and safety managers were better qualified.

It also discovered there were 60% fewer accidents when subcontractors were vetted by health and safety specialists.

An IOSH spokesman said:

"Currently, the health and safety profession is not legally regulated, meaning that almost anyone can call themselves a health and safety expert, without any qualifications or experience.

"IOSH, the chartered body for health and safety, is calling for UK-wide legal minimums for all those practising as health and safety professionals."