Moscow election officials ruled Friday that Alexei Navalny could run for mayor in a hotly contested September poll after warning they could bar President Vladimir Putin's top critic from the race.
Navalny, the 37-year-old leader of Russia's opposition movement, has faced numerous probes into his lively Western-style campaign, which has taken him to second position in opinion polls behind the current Kremlin-backed mayor Sergei Sobyanin.
On Friday, the Moscow electoral commission opted not to disqualify Navalny from the September 8 race, instead issuing him with a verbal warning after police confiscated allegedly illegal campaign materials.
"Alexei Navalny is a young, inexperienced candidate, who is standing for the first time," the commission said in a statement.
"We are sure that in the future the candidate will take his mistakes into consideration and won't allow violations of the law by members of his campaign team."
"The Moscow electoral commission gave me a verbal warning. What a scandal," Navalny responded sarcastically on Twitter.
Friday's decision came after police last week raided a Moscow apartment and confiscated unregistered posters and flyers that Navalny said his supporters had created independently.
A source in the electoral commission told the Interfax news agency there was no documentary proof that Navalny had ordered the materials.
Electoral commission head Valentin Gorbunov had said on Thursday that the body could consider disqualifying Navalny if it ruled the violation was sufficiently serious.
Earlier this month, Russian prosecutors accused Navalny of breaking the law by receiving donations from foreign nationals, after allegations made by the leader of the Kremlin-friendly nationalist Liberal Democratic Party, Vladimir Zhirinovsky.
Navalny, a charismatic lawyer who rose to fame during anti-Putin rallies that broke out in Moscow in the winter of 2011, denied the claim and said all his funding for the mayoral race was being gathered in strict accordance with the law.
It is unclear whether Navalny will be allowed to continue his campaign until the September 8 poll.
He was convicted in July of embezzlement and sentenced to five years in prison in a disputed verdict. In a surprise move, he was freed pending appeal and allowed to stand as a candidate.
The authorities appear keen to ensure that Sobyanin, who was appointed by the Kremlin in 2010, is seen to win a legitimate contest, while a stream of allegations muddy Navalny's reputation with voters.