* Proposal relates to "supercredits" for low-emission cars
* Wants to be able to save supercredits from before 2020
* Proposal could allow continued manufacture of big cars
BRUSSELS, June 7 (Reuters) - Germany has put forward a fresh proposal on regulating carbon dioxide limits for cars sold in the European Union, which campaigners say is a last-ditch attempt to dilute a new emissions law.
Germany has been pushing for months for greater flexibility in implementing an emissions goal of 95 grams of carbon dioxide per kilometre (g/km) as an average across new EU vehicles from 2020.
But votes in the European Parliament so far have backed a fairly robust version of the European Commission's original proposal.
Ireland, holder of the rotating EU presidency, is hoping for agreement between member governments, the European Parliament and the Commission by the end of this month.
The loopholes that Germany wants to maximise, known as supercredits, would allow its premium carmakers such as Daimler and BMW to keep producing powerful, relatively high emission cars - provided they also make very low-emission vehicles, such as electric cars.
The new German proposal, seen by Reuters, argues that being able to save supercredits from before 2020 so they can be used later is the only way to ensure no time is lost in getting Europe on the path to highly efficient vehicles.
Environmental campaigners disagree and say Germany is pushing for a further weakening of the 95 g/km target. Already they say the effect of the version backed by the European Parliament would increase the target to 97.5 grams, slightly easier than the Commission's plan.
"This new proposal for banking of supercredits is the same accountancy trick that has already been rejected by the European Parliament and most countries," said Greg Archer, from campaigning group Transport & Environment. "It is a desperate attempt by Germany to protect the interests of premium carmakers."
The executive European Commission and many EU member states say the number of supercredits should be strictly limited or would risk diluting the effectiveness of the law.
Unlimited supercredits could allow the manufacture of electric cars for which there is little or no demand, while allowing just as many polluting vehicles as before on to the roads, campaigners say.
The European car industry association ACEA says supercredits are necessary and are used elsewhere in the world to encourage innovation.
German industry representatives take a similar line.
"From our point of view, supercredits do not weaken the 95 gram target. In fact, they are rather a free seed-funding for the community or state in order to help pave the way for new technologies," Daimler spokeswoman Sandra Hahn said in an email.