The rules were introduced under Labour in 2007 to make clients and architects more responsible for safety.

But clients claim the changes have simply upped costs for the construction industry without improving standards.

A report by researchers Pye Tait, commissioned by the British Property Federation (BPF) and the Construction Clients’ Group (CCG), found that two-thirds of companies have no knowledge of the legislation whatsoever.

The report shows scant knowledge of the legislation among those clients that do not have a regular involvement in construction.

Jail terms or unlimited fines could await companies or individuals who fail to comply with the legislation – even though two-thirds of ‘infrequent’ clients had never heard of the regulations.

Industry groups want the government to overhaul the regulations and engage more widely with business to ensure that anyone likely to commission construction work understands their responsibilities and knows where to get help.

For companies whose main operations include construction, such as property developers, the study has found that the legislation has not led to a substantial reduction in health and safety risks in construction, while costs and the level of administration required for compliance have risen.

James Preston-Hood, CCG board director and chair of the Construction Clients Group said: “The report bears out our own experiences; the regulations have not led to a substantial increase in site safety, while the costs and administration associated with complying have risen.”

Liz Peace, chief executive of the British Property Federation said: “Health and safety is something which organisations should manage as carefully as their balance sheets.

“It is clear from the research that this message is not permeating outside of the regular client community and at a time where the construction industry is suffering under huge cuts, it is vital we do not up the burden further.”

Jon de Souza, chief executive of the Construction Clients’ Group said: “The findings of the report confirm that changes are needed to the legislation to deliver their intent.

“We would like to see the Health and Safety Executive commit to a root and branch review of the regulations and also refresh their communication strategy with the general business community.”