Former prime minister Kasyanov was denied registration for the March 2 election last week, when the Central Election Commission (CEC) said over 13% of signatures he collected to support his presidential bid were faked or unverifiable. His support team rejected the forgery claims as "political pressure."
Press secretary Yelena Dikun said Kasyanov has already submitted his appeal. As Kasyanov filed the appeal within 10 days from the CEC decision, his name could still be entered on the ballot papers if the court overturns the ruling.
A statement on the politician's website said earlier: "We are filing a complaint with the Supreme Court over the CEC's decision to deny me registration as candidate for president. Two million people have given me their support, and I must uphold their position to the end."
Under Russian law, presidential candidates have to collect at least 2 million signatures in their support. The share of invalidated signatures cannot exceed 5% of the total.
Four candidates have passed registration procedures: First Deputy Prime Minister Dmitry Medvedev, Communist leader Gennady Zyuganov, the ultranationalist Liberal Democratic Party leader Vladimir Zhirinovsky and Andrei Bogdanov, the leader of the tiny pro-Western Democratic Party.
Medvedev, who has been publicly backed by President Putin, is the clear front-runner.
