The Central Elections Commission on Wednesday officially registered billionaire Mikhail Prokhorov as a candidate for the March 4 presidential election, RIA-Novosti reported.
As an independent candidate, Prokhorov had to submit more than 2 million signatures from supporters to be included on the ballot.
Prokhorov is the fifth candidate to qualify for the ballot, joining Prime Minister Vladimir Putin, Gennady Zyuganov of the Communist Party, Sergei Mironov of the A Just Russia party and Vladimir Zhirinovsky of the Liberal Democratic Party.
The ballot has now been finalized and will include only those five candidates, RIA-Novosti reported Wednesday.
Yabloko candidate Grigory Yavlinsky's presidential run is expected to be halted later this week, after the elections commission announced that it had found an excessive number of errors in the signatures he submitted. Commission secretary Nikolai Konkin said the registration of Yavlinsky would be officially refused at the end of this week.
Prokhorov said earlier this week that the failure to register Yavlinsky as a candidate deals a blow to the vote's legitimacy. Putin's spokesman, Dmitry Peskov, responded to Prokhorov's comment Wednesday, saying he is convinced no such problem exists.
"If one of the candidates could not collect the necessary number of votes [for registration], that does not give cause to assert that the election is illegitimate," Peskov said, according to RIA-Novosti.
Peskov said Tuesday that Yavlinsky's electorate is "rather insignificant" and that neither Yavlinsky nor the other candidates pose a danger to Putin's chances in the election.
"I don't think [Putin's] opponents represent an electoral threat for him. Vladimir Putin is the leading politician in our country, a politician with an inarguable rating . . . and a politician who is rather confidently running in the upcoming presidential election," Peskov said in an interview aired on radio station Kommersant-FM.