The Supreme Court on Tuesday heard a Greenpeace complaint against Prime Minister Vladimir Putin's order to reopen a Siberian paper mill that the group says pollutes the world's largest freshwater lake.
In January, Putin ordered the Baikalsk Pulp and Paper Mill to be restarted on the shores of Lake Baikal. The plant had been mothballed in late 2008 amid disputes over pollution.
Putin's decision was met with dismay from environmentalists and relief from locals, who praised him for trying to bring back almost 1,500 jobs to the poverty-stricken region.
The plant partially reopened on May 21 to provide electricity, said Mikhail Kreindlin, a Greenpeace lawyer and expert on protected areas.
"We hope our case will make them change their mind and permanently shut it," he said after the hearing.
Kreindlin and court representatives said a ruling on whether to overturn the decree would likely come this week.
It would be highly unusual for the Supreme Court to overturn a government decree.
Greenpeace argues that reviving the mill will dump toxic waste into Baikal and may cause irreversible damage to the lake, which contains a fifth of the world's fresh water and hosts 1,500 species of plants and animals. UNESCO put Lake Baikal on its list of World Heritage sites in 1996.
Before going to court, Greenpeace asked UNESCO to dissuade the government from reopening the mill, arguing that doing so would break a promise to the UN's cultural arm.
In an open letter to President Dmitry Medvedev, it said Russia had signed a convention obliging the government to do its best to preserve the treasure for future generations.
Amid protests by environmentalists last month, Medvedev said environmental problems at Lake Baikal were being ignored by Putin's government. Medvedev has only rarely criticized the government.
"We think we defended our case well," Kreindlin said.
Tycoon Oleg Deripaska held control in the plant through a subsidiary of his Basic Element company from 2002 until earlier this year.
Deripaska's Continental Management subsidiary now owns a 25 percent stake in the plant after selling a 25 percent stake to Continental Invest, a company controlled by businessman Nikolai Makarov, in a deal that closed March 31.