German Chancellor Angela Merkel said her government vetoed tough EU automotive carbon emission limits to protect jobs in her country's powerful car industry, in comments published Friday.

Germany, which often bills itself as a star pupil in the fight against climate change, has led a group of EU members that torpedoed a draft for tighter passenger car restrictions being debated in Brussels.

The plan to limit CO2 emissions to 95 grammes per kilometre by 2020 was meant to reduce the role of gas-guzzling cars in warming the planet's climate, melting ice caps and raising sea levels.

Asked by national news agency DPA why Berlin opposed the move, Merkel made the point that Germany's car sector -- with global giants including VW, Daimler-Benz and BMW -- on average makes bigger cars than others and would therefore be disproportionately affected.

Merkel, who faces elections on September 22, said: "The German auto sector directly and indirectly creates hundreds of thousands of jobs, far beyond our borders. This can't be ignored if, for example, a decision is made in Brussels about new CO2 emission standards for carmakers.

"Manufacturers whose fleets are made up of small as well as big models, or overwhelmingly of smaller cars, are better placed to meet these guidelines.

"But some of our producers which build mainly larger cars -- even if they may be the most efficient and innovative among the big cars -- would have suffered a major disadvantage under the existing EU plans, which would have threatened jobs, including in Germany."

The chancellor, who has strongly pushed for global action on climate change, added: "Just to avoid misunderstandings: I very much support challenging requirements for manufacturers. The auto industry must do its part for climate protection. But what we ask of it must be technically feasible."

Merkel was often dubbed the "climate chancellor" after her bold decisions following Japan's 2011 Fukushima nuclear disaster to phase out fossil fuel and atomic power over coming years in favour of clean renewables such as wind and solar.

But critics also accuse her conservative government of putting the interest of the powerful automotive industry, a key export earner in Europe's biggest economy, ahead of environmental goals.

News that a minister of state in Merkel's chancellory, Eckart von Klaeden, will later this year, after the election, become chief lobbyist at Daimler has sparked charges of unhealthy ties and conflict of interest.

Asked about the controversy, Merkel replied: "It is the federal government's sole aim to harmonise both economic and environmental requirements, nothing else."