The Supreme Court on Tuesday rejected a complaint by opposition politician Gennady Gudkov over the State Duma's decision in September to deprive him of his seat in parliament.
Gudkov, a member of the Just Russia party, was stripped of his Duma seat after the Investigative Committee said he was involved in entrepreneurial activity, which is illegal for Duma deputies. In December, the Constitutional Court sanctioned the Duma's decision to kick him out.
The evidence of Gudkov's engagement in business activity included a document from the Kolomensky Stroitel construction materials market that bore Gudkov's signature.
But at a Supreme Court hearing Monday, Gudkov's wife, Maria, who runs the company, said the document had been made by the company's lawyers under pressure from authorities.
Gudkov, who was among the organizers of anti-Kremlin street protests in Moscow over the last 14 months and is a member of the opposition Coordination Council, said the Duma's decision to oust him was politically motivated.
After Tuesday's hearing, Gudkov said the Supreme Court demonstrated its dependence on the Kremlin.
"So the Supreme Court has sanctioned out-of-court reprisals as a lawful way of political struggle," he wrote on Twitter. "The decision was predictable, but it feels nasty anyway."
Gudkov has said that if he lost his Supreme Court appeal he would file a complaint with the European Court of Human Rights.