A Russian liberal opposition leader said his coalition submitted a court appeal on Friday of a Justice Ministry ruling that denied it the party registration needed to participate in December parliamentary elections.
The ministry's denial of registration last month to the Party of People's Freedom, which unites several previously splintered opposition groups, sparked criticism from the United States and European Union.
"In the document that we received from the Justice Ministry, there are five arguments for our rejection, but not a single one holds up to scrutiny," Vladimir Ryzhkov, a co-leader of the party and former lawmaker, told Reuters.
"We submitted the appeal at 10 this morning," he said.
Among its reasons for rejecting the opposition party's application in a terse ruling last month, the Justice Ministry said the 46,000 signatures of supporters required for registration included dead people and teenagers.
Rhyzkov has denied those allegations.
President Dmitry Medvedev said last month the People's Freedom Party still had a chance to register if it corrected the registration rules violations the ministry cited for its decision.
But Ryzhkov said that even if the appeal was won and the party registered, there would not be enough time to fulfill other legal requirements to participate in the Duma vote.
Ryzhkov leads the party along with Mikhail Kasyanov, prime minister from 2000-2004 during Vladimir Putin's first term as president but now a fierce critic, former Deputy Prime Minister Boris Nemtsov and former Deputy Energy Minister Vladimir Milov.
The ministry ruling has underscored Western concerns about the legitimacy of the December election to the State Duma, Russia's lower parliament house, and a March 2012 presidential vote in which Putin, now prime minister, has said he may run.
Two decades after the 1991 collapse of the Soviet Union, rights groups and Kremlin opponents say authorities often use technicalities to bar some opponents from elections and distort the voting results in favour of the ruling party.
Electoral officials dismiss such claims. Opinion polls and regional election results indicate Putin's ruling United Russia party may have trouble retaining its two-thirds majority in the Duma.