Andrei Illarionov, President Vladimir Putin's chief adviser on economic issues, said the agreement placed "significant limitations on the economic growth of Russia" and could not be ratified by Moscow in its current guise.

But Ewa Hedlund, a spokeswoman for EU Environment Commissioner Margot Wallstrom, played down the Russian position, which, if confirmed, effectively means the Kyoto Protocol cannot come into force.

"It's nothing new," she told AFP.

"He said the same thing, almost, in September-October during the climate change conference in Moscow," Hedlund said.

"According to the information we have, the assessment that has been done by the Russian government itself on the implications of the protocol for Russia never raised any economic concerns.

"So this is a purely political statement. We still hope that Russia sticks to the commitment to ratify."

Since the world's biggest single polluter, the United States, has rejected the 1997 Kyoto accord, the agreement can only take effect under its complex ratification rules once it has been approved by Russia's parliament.

At the conference on climate change in September, Putin said Russia was undecided about signing the protocol and would make its decision in line with its national interests.

"Russia has not said formally 'no' to ratification. They have not come to the European Union and to the other parties and said 'no, we're not ratifying'," Hedlund added.

Speaking Tuesday before Illarionov's intervention, Wallstrom said the Kyoto agreement was being "held hostage to an internal political process" in Moscow.

"The Kyoto Protocol is not dead. It has maybe held its breath for a little while as we are all waiting for the Russian ratification," she told a news conference.

"I believe that Russia will ratify.

"But the best thing we can do... is to show we are serious about our commitments to the Kyoto Protocol," she said, unveiling new figures that show the EU is failing to meet its own targets to reduce greenhouse gas emissions.

Wallstrom also ridiculed assertions by some in Russia, repeated by Illarionov, that global warming could benefit the country by reducing its steep bills for heating, lighting and winter clothes.

Permafrost in Russia's north would start to melt, farmland would be lost and coastal areas flooded, the Swedish commissioner said.

"I think it is very short-sighted to make these kinds of jokes. If you think education is expensive, try ignorance."

SPACE.WIRE