On March 23, the Supreme Court granted a request by election regulators to close down the right-wing party, nine months ahead of parliamentary polls.
The Federal Registration Service said in its lawsuit that the number of party members and local branches had fallen short of legal requirements that came into effect on January 1. Under the requirements, parties that fail to comply must either be transformed into public movements or closed down.
The Republican Party, set up on the basis of the Democratic Platform of the Soviet Union's Communist Party in 1990, was last registered with the Justice Ministry in August 2002.
A co-chairman of the party, Vladimir Ryzhkov, said he disagreed with the court's decision, and the party, known for its strong opposition to the Kremlin's military campaign in Chechnya in the 1990s, filed three appeals with the European Court of Human Rights in Strasbourg.
"Tomorrow we will send a letter to the European Court of Human Rights asking it to give priority to our appeals, as we intend to take part in the upcoming elections to the State Duma," Ryzhkov said.
Earlier he said the court had failed to closely examine the evidence provided by the party, after representatives brought five boxes of documents into the courtroom providing proof that the party had 58,166 members.