France, holder of the rotating EU presidency, hopes to forge a compromise among the 27 member states by December when negotiators meet in Poznan, Poland, to discuss a new global deal on limiting greenhouse gas emissions.

"For Poland, the current proposal is still more a threat than an opportunity, I think. If the EU wants to set an example in Poznan, it has to work out a consensus within the bloc first," Piotr Serafin, a deputy head of the Office of the Committee for European Integration, told a climate change panel organised by a pro EU think-tank on Tuesday.

"Only then will it be able to act as a role model on the world stage. Tension in the global negotiations will be between rich and poor. And you cannot force China or India into a deal. Europe must work out its own consensus in order to exert pressure on the global stage."

Poland fears ambitious EU goals for curbing emissions would result in energy price increases of up to 70 percent. With fellow ex-communist states Hungary, Slovakia, Bulgaria and Romania, it has signed a statement calling for more debate on Brussels' plans.

Some political analysts have seen the declaration of the five ex-communist countries as an attempt to build up a blocking minority in the EU that would force the Commission to seek a compromise on its plans.

Polish Prime Minister Donald Tusk said in June Warsaw might try to block the plan if Warsaw's demands were not met.

"It would be hard for me to imagine a situation in which the climate package -- with all its long-term consequences -- would be approved by one group outvoting the other," Serafin said. "Anyway, the target date set by the French presidency may turn out to be a bit too ambitious."

Poland, which derives about 95 percent of its electricity from coal, wants to delay Commission plans for the start of full auctioning of carbon dioxide emission permits in 2013.

At present, companies are granted some emission permits for free but in the future they will have to buy all permits, increasing their costs. (Reporting by Gabriela Baczynska, editing by Andrew Dobbie)