The State Duma on Friday backed a draft law banning those convicted of crimes from running in elections for at least 10 years, which a lawyer for opposition leader Alexei Navalny said would prevent him from competing in the 2018 presidential race.
Critics accuse President Vladimir Putin of using courts to sideline rivals such as Navalny, who said he wants to challenge the ex-KGB officer in a presidential election.
Navalny, 37, was handed a suspended five-year sentence for theft in September in what he said was a politically motivated court case.
Any individual charged with either a "serious crime" — punishable by at least five years in prison — or most economic offenses will be barred from elections for 10 to 15 years after the criminal record is cancelled, according to the bill.
The bill is an amendment of an existing law that bans ex-prisoners from seeking election for life. The law was ruled unconstitutional by the Constitutional Court earlier this year.
Only five Duma deputies voted against the bill, which was supported by 332 votes in the first of three readings.
In its current form, the law will prevent Navalny from running in the 2018 presidential elections, though it could be changed in subsequent second and third readings before it passes, Navalny's lawyer Olga Mikhailova said.
"One should see which version will make it into law," she said.
New theft and money laundering charges were leveled in October against Navalny, an anti-corruption blogger who has campaigned against graft among Russia's ruling elite and ran unsuccessfully in Moscow mayoral elections this year.
Despite the biggest protests last year against his 13-year rule, Putin remains by far Russia's most popular politician. Navalny's popularity is limited mostly to western Russia's urban centers of Moscow and St Petersburg.