They say the project, expected to cost US$13 billion, would flood an area more than ten times the size of New York City and drive about 2,000 Evenki -- out of 28,000 in Russia -- from their traditional villages and pasture lands.

Pavel Sulyandziga, first vice president of the Association of Indigenous Peoples of Russia's North, Siberia and Far East, said the groups opposing the dam have approached all the candidates in the presidential race.

"If the Evenki have their land destroyed by this project then they will not be able to carry out their traditional customs -- deer herding and hunting -- on their land, " he said at a news briefing. "And that means they will cease to exist."

Russia's state hydro-electric power company, RosHydro, said it is looking at plans to build an 8,000 megawatt station at Turukhansk on the Lower Tunguska River in northern Siberia that would flood some of the Evenki pasture land and villages.

In 1998, the Soviet Union cancelled plans to construct a giant dam at the site after Soviet leader Mikhail Gorbachev questioned the policy of building giant hydro-power stations.

But Anatoly Chubais, the chief of Russia's power monopoly, has said the revived project will change the face of the region, bringing railways, roads and factories to the desolate spot.

A spokeswoman for RosHydro said the project had not yet been approved and local concerns would be addressed, with all of those displaced given compensation.

"We are working out the project at the moment and looking at the ecological impact," she said. "If it is approved then it will have to go through all the proper environmental studies."

The Evenki said they were being exposed to a new threat to their way of life after only just surviving Communist attempts to "Sovietise" their culture.

"The Soviet Union used to call on us to build a 'bright future' without paying any attention to the differences in culture and traditions of indigenous peoples and so destroyed a whole way of life," local Evenki said in a petition.