France tried to put the brakes on a German effort to skew European fuel efficiency legislation in favour of heavier cars on Wednesday amid fears that it would price the country’s small models out of the market.

With the European Commission set next month to unveil proposals on how to cut carbon emissions from new cars by a quarter by 2012, Jean-Louis Borloo, French environment minister, pointed to figures showing the gap between the two countries’s carmakers widened further last year.