A Kremlin critic and former Russian Prime Minister, Mikhail Kasyanov, has handed in a petition supporting his bid to contest presidential polls in March.
Mr Kasyanov says he has enough support to run for president
Mr Kasyanov says he has submitted two million names in support. The election commission will now check his papers.
Russian law requires candidates who lack the backing of a party with seats in parliament to deliver the petition.
Mr Putin's nominee to succeed him as president, Dmitry Medvedev, is widely expected to win the vote.
Mr Putin is constitutionally obliged to step down at the end of his second presidential term this year.
The president remains highly popular with Russians and is expected to retain influence at the Kremlin.
Late last year, Mr Putin announced he intended to become prime minister if Mr Medvedev was elected to the presidency.
Mr Kasyanov arrived at the election commission office in Moscow on Wednesday, accompanied by a fleet of minivans containing the paperwork for his presidential bid.
He told the BBC he did not believe the election would be free or fair.
But, he said, he was running for the presidency in order to defend the "democratic" institutions he had empowered during his time in government.
"Today I feel that all my... results are being destroyed by this current regime," he said.
Mr Kasyanov is thought to have little chance of winning the race.
He was sacked as prime minister in 2004 and subsequently investigated for corruption - a move he claimed was politically motivated.
According to Richard Galpin, the BBC's Moscow correspondent, Mr Kasyanov will be the only real opposition figure in the presidential race if his candidacy is approved.
Other contestants include Vladimir Zhirinovsky of the nationalist Liberal Democratic Party, and the Communist Party leader, Gennady Zyuganov.