MOSCOW (Reuters) - One of President Vladimir Putin's closest allies said on Tuesday he would resign as Moscow mayor and stand in snap elections, seeking a new five-year term.
Opposition leaders, who hope to reinvigorate flagging street protest against Putin's 13-year rule with a rally next week, criticized the move, saying it was timed to rob them of the chance to campaign for a rival candidate.
Polls show Mayor Sergei Sobyanin is all but guaranteed to win, ensuring Putin would have his man running the capital if the president seeks a fourth term in elections in 2018.
Sobyanin, 54, who was appointed by the Kremlin in 2010, said he would ask Putin to approve holding what would be the capital's first direct mayoral elections in a decade on September 8.
Although most mayors in Russia are elected, the mayors of Moscow and Russia's second city St. Petersburg share the same status as governors, who were appointed by the Kremlin until political reforms passed in 2012 reinstated direct elections.
Sobyanin replaced Yuri Luzhkov after he fell out with the Kremlin after an 18-year tenure.
Prime Minister Dmitry Medvedev was upbeat on Sobyanin's chances to win the top job in Moscow, which generates a quarter of Russia's GDP but has also seen the biggest anti-Kremlin protests.
Maria Lipman, an analysts with Carnegie Moscow Center think-tank, said about half of Moscow's population backed Sobyanin, with potential rivals trailing way behind.
"Moscow has the biggest concentration of people critical of the authorities and the longer this situation goes on, the worse things could prove for Sobyanin," she said.
"It's safer for Sobyanin to stand in elections now. This is an attempt to stabilize the situation in Moscow now and not wait and risk it deteriorating."
Protest leader Alexei Navalny, who has declared his ambition to challenge Sobyanin, denounced the mayor's surprise announcement as "vile clownery" and an attempt by the Kremlin to tighten its grip on the city.
Navalny, who writes a blog about corruption, will run unless he is convicted of theft in a trial that Kremlin critics see as an attempt to sideline him from politics, his spokeswoman, Anna Veduta, said.
Another possible contender, Mikhail Prokhorov, one of Russia's richest men, could also be barred from running under a new law that bans officials from owning assets abroad.
Commenting on the mayor's move, Prokhorov said in a statement: "It is only the naive who cannot see this as a ploy to win time while political opponents have not yet had time to mobilise."
By staging the election campaign during the summer, he said, the authorities are banking on a lull in political activism during the vacation period to play in Sobyanin's favour.
(Reporting by Gabriela Baczynska and Maria Tsvetkova; Editing by Alissa de Carbonnel and Robin Pomeroy)