Russian opposition leader Alexei Navalny cannot run for presidency because of his criminal conviction, the Central Election Commission, said in a statement on Friday.
"Navalny does not have passive suffrage," said the statement, meaning he was ineligible to run for office.
Navalny was found guilty of embezzlement in February and given a five-year suspended prison sentence in a court case he says was organized to stop him running for president.
Navalny has become the most prominent opposition challenger after organizing some of the biggest anti-Kremlin protests in years, seeking to leverage public anger over what he says is grotesque official corruption to boost his popularity.
Putin, who has dominated Russia's political landscape for 17 years, is widely expected to run for what would be his fourth term, but has yet to confirm he will do so.
Last month Navalny was jailed for 15 days by a Moscow court for resisting police orders after organizing a wave of nationwide protests against government corruption that rattled authorities.
Navalny was arrested as he walked to a protest in Moscow and spent the night in jail before appearing in court.
Tens of thousands of anti-corruption protesters took to the streets across Russia on Sunday in the biggest show of defiance since 2011-2012 anti-government protests.
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