BRUSSELS (Reuters) - A top European court advisor has rejected a complaint by British vacuum cleaner firm Dyson that EU energy labels underplay the efficiency of its bagless devices, in an initial opinion that could sway a court ruling next month.
Dyson, whose devices were the brainchild of billionaire British inventor James Dyson, says ordinary cleaners become less energy efficient as their bags become clogged with dust, unlike Dyson's bagless cleaner.
It says the EU's energy efficiency labels fail to recognise this. In a separate case, Dyson, whose founder was among campaigners for Britain to leave the European Union, has challenged the labelling system itself.
Dyson took legal action against BSH, which sells home appliances under the brands Siemens and Bosch, saying that it was misleading consumers by failing to mention that the tests were carried out with an empty dust bag.
A Belgian court referred the case to the Court of Justice of the European Union (ECJ), the highest EU court.
Advocate general Henrik Saugmandsgaard Oe was giving an initial opinion on Thursday as part of that process.
Oe said EU law made the energy label compulsory and also set out its format and the information to be included in it. The methodology of the test was not part of that information.
He concluded that EU law precluded the use of supplementary labels on energy efficiency as these would undermine the aim of the law -- to standardise information for consumers.
The ECJ will rule on the matter in the coming months. Judges typically follow the line of the advocate general but are not bound to do so.
Dyson lost the initial case at the General Court, the second-highest EU court, but the ECJ upheld an appeal in 2015 and ordered a review. The lower court, it said, had failed to establish that a test on cleaners with full bags could not be easily reproduced.