The pipeline is about 1,200 kilometres (750 miles) long and it will run from Vyborg, in Russia, under the Baltic Sea, to Greifswald, in northern Germany.
Once construction is completed at the end of 2010, the pipeline will supply Russian natural gas to customers all over Europe.
There is a perception that the pipeline was a project drawn up between Russia's state energy company Gazprom and Germany, and other countries claim they were not consulted.
Poland and the Baltic states say they feel they have been bypassed, claiming they will also lose transit fees.
The new Polish Prime Minister, Donald Tusk, says he will continue to push for the planned Russian-German gas pipeline to pass through Poland, rather than under the Baltic Sea.
Finland's environmental agency wants the pipeline to be moved further south.
"We are generally in favour of completing the pipeline project in order to have an alternative source of supply," says Jorma Korhonen, the director general of the Finnish Department for External Relations.
"But environmental factors have to be taken into account. We are concerned about the impact on the environment."
"This pipeline involves huge risks. We do not know what will happen when the seabed is disturbed," says Juha Aromaa, a spokesman for Greenpeace.
"The Baltic Sea is polluted and some of the poisonous substances on the seabed could re-surface.
"We are pushing the boundaries of surveys along such a long survey corridor."
The Gulf of Finland was heavily mined, and along with chemicals, were dumped in the sea during World War II.
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