Germany has been pressing for more leeway to be given to luxury and sports cars but this has upset France, whose automobile manufacturers focus on smaller, more fuel-efficient cars.
Now the row has gone public, with French environment minister Jean-Louis Borloo writing in the Financial Times: “By virtue of the polluter-pays principle, those with the biggest pollution should make the biggest progress in reducing emissions.
“Nothing justifies giving a bigger right to pollute to the buyer of a bigger vehicle.”
But Germany is proposing that heavier cars could emit more CO2 than the preferred 130g/km cap.
The row comes as campaign group Transport and Environment noted that in 2006, German manufacturers increased CO2 emissions from newly-sold cars by 0.6% on average.
French and Italian car makers reduced emissions by 1.6%.