The EC's Energy Performance Directive is one of the least successful pieces of legislation ever introduced, according to leading business law firm LG.

According to its poll of law firms in 18 countries, improving energy efficiency is a low priority for businesses in most European countries. The findings come as legislation implementing the directive takes further effect in the UK today.

All commercial buildings marketed for sale or letting in the UK will need an EPC grading their energy efficiency. However, LG says the UK and Switzerland are the only two of 18 countries surveyed that report a relatively high level of interest in or awareness of energy efficiency of buildings.

In newer accession states, including the Czech Republic, Latvia, Slovenia, Estonia, Ukraine and also Belgium, businesses showed little or no interest in energy efficiency. Even in developed markets considered "green", like Germany, Sweden and the Netherlands, interest was no more than moderate.

"This has been one of the most problematic directives ever produced by the European Commission," said Catherine Diggle, partner at LG and a member of the DCLG's commercial advisory group.

"Many countries are still lagging behind with their implementation of it, and there have been more than 20 infringement cases.

“Overall, on the EC's own assessment, this directive has been the worst performer in terms of timely implementation and we now expect it to be re-issued later in the year in a simpler and stronger form."