Mitvol, the deputy head of the environmental regulator Rosprirodnadzor, told RIA Novosti: "I cannot work here. There is no interest for me here. I need work, not just a salary. I have submitted a request for a vacation with subsequent resignation. From April 28, they can look for someone else to fill my place."
A few hours after the announcement, Natural Resources Minister Yury Trutnev, who oversees the environmental regulator, accepted the resignation.
"The minister has accepted Mitvol's resignation," a spokesman for the Natural Resources Ministry said.
Mitvol was appointed to the post in April 2004, but came to international attention in late 2006 when he led a campaign against oil major Shell that resulted in a lucrative project being sold to Gazprom.
Reports of Mitvol's resignation had been circulated several times since January 2008, when Vladimir Kirillov became head of the agency. Mitvol was critical of the nomination.
A senior official at the Natural Resources Ministry, Rinat Gizatullin, expressed disappointment on Monday over Mitvol's decision to resign.
Mitvol "can be judged in different ways, but his work in protecting the environment and popularizing environmentalism has brought major positive results," he said.
Mitvol himself complained that he had been deprived of much of his authority in recent moths. He also suggested that he had been sidelined for standing up to corruption.
"April 15 marks five years since I assumed civil service, and I must say that during this time, many of my acquaintances have made a lot of money, while I have managed to make as many enemies," he said.
As well as the Shell case, Mitvol also spearheaded campaigns over ExxonMobil-led Sakhalin-I, the Kovykta gas field developed by TNK-BP, and a pulp mill pumping waste into Siberia's Lake Baikal, which was finally closed down earlier this year.
Although in most cases the environmental damage Mitvol highlighted in Sakhalin, including deforestation, toxic waste dumping and soil erosion, was well documented by environmental groups, the campaigns were often portrayed in the Western media as part of the Kremlin's drive to bring key oil and gas assets back under its control.
