Manufacturer Dyson, which is based in Malmesbury, is mounting a legal challenge against the EU’s labelling policy for vacuum cleaners because it says it gives a misleading impression of the firm’s products.

The firm’s founder Sir James Dyson said the EU’s energy efficiency ratings were based on dust-free lab conditions, favouring “old-fashioned technology”.

He said home performance was “very different to that in the laboratory”.

Sir James has pioneered the bagless vacuum cleaner.

From September 2014, all vacuum cleaners sold in the EU will be rated according to their performance and energy efficiency, in an effort to reduce carbon emissions and save energy.

It wants buyers to take the environment into consideration when they buying appliances.

Dyson said it had launched a judicial review at the European General Court in Luxembourg, because it felt the rating system was misleading.

“The regulations stipulate that vacuums should be tested in laboratory conditions: empty and with no dust,” said the firm.

“This does not simulate real-life conditions and is not representative of the view of testing and standards bodies across Europe.”

Dyson said its bagless design meant its cleaners did not clog with dust and therefore wasted less energy. It also said the EU tests did not take into account the cost, “on both the pocket and the planet”, of replacement bags and filters for older types of vacuum cleaner.

The firm said it supported the aims of making the environmental impact of machines easier to understand.