The printed commercials for the range, including the ZE (pictured) due out next year, said the cars produced 90% less emissions than current diesel models.

However, the small print pointed out this was due to the French average electric mix, which gets a much larger amount of its power from Nuclear than the UK.

As a result standard French electricity has much lower emissions than Britain’s and one person complained to the Advertising Standards Authority (ASA) that the ad was therefore misleading.

In a hearing today (May 5) Renault claimed the ZE models would be available on the UK market from 2011 onwards and maintained that the ad attempted ‘merely to draw comparisons between internal combustion engines and their effects versus electric vehicles’.

The firm said it was not misleading and that it did make reference to the source of electricity being the French average mix.

In its ruling the ASA ruled readers were ‘unlikely to understand’ the difference between electricity generating mixes in France and the UK, and how that would affect CO2 savings in different countries.

A spokesman said: “Consequently, we considered they were likely to expect that the figure quoted in the body of the advert was representative of the typical savings possible in the UK.”

The ASA also ruled the advert should not be printed again in its current form.

Luke Walsh

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