Moscow Mayor to Step Down to Gain Election Edge MOSCOW - The mayor of Moscow said on Tuesday that he would like to step down two years before the end of his term and hold snap elections on Sept. 8, radically accelerating the election cycle in an apparent attempt to minimize the risk of political change. The announcement came unexpectedly, since in recent months the mayor, Sergei S. Sobyanin, had publicly said he was not in favor of speeding up the mayoral race. There is little doubt that Kremlin officials are worried about a series of coming regional and municipal elections that were reintroduced last year as part of a political overhaul package. Anxiety is especially high in Moscow, which has noticeably cooled to President Vladimir V. Putin. It will be the first mayoral election here in a decade. If President Vladimir V. Putin accepts Mr. Sobyanin's resignation and the election is held in September, it would leave little time for opposition forces to organize a campaign. The months of July and August are political doldrums here, and activists are demoralized, helplessly watching the trials of both the protest leader Aleksei A. Navalny and the two dozen protesters who were caught on videotape resisting the police in demonstrations in May last year. The plan suggests that Kremlin forecasters are not expecting economic conditions or the political mood to improve in the near future. They may even have feared that Mr. Sobyanin would not win in 2015, when his current term ends. "The protesters, these "modernized Russians," may not be a political force, but their mood is a factor that cannot be ignored, and they are getting angrier and angrier," said Maria Lipman, an analyst at the Carnegie Moscow Center. The Kremlin, of course, and Putin personally, is trying to avert risk, to minimize the risks even if they are not too high. Among the politicians who have expressed interest in running for the post is Mr. Navalny himself, but he is on trial in the city of Kirov, on embezzlement charges that could bring a sentence of up to 10 years. Another is the billionaire Mikhail D. Prokhorov, who situated himself as a candidate for middle-class liberals in the 2012 presidential election, but who seemed to withdraw abruptly from the political stage after that. Mr. Prokhorov said Tuesday that he would consult with his lawyers before deciding whether to run, and condemned Mr. Sobyanin's decision as a result of "fear ahead of clean elections." "Only the naïve do not see a trick here - picking a time when it is impossible for political opponents to mobilize, and spend the brief summer organizing a campaign, during the season of summer cottages and holidays," he wrote on his blog. Most analysts on Tuesday said Mr. Sobyanin would win easily in September. Mr. Sobyanin has a blandly bureaucratic style, and served for years as Mr. Putin's chief of staff before being appointed mayor. Still, he has remained reasonably popular among Muscovites even as they cooled to the current government - Mr. Putin won just under 47 percent of the vote in 2012, his lowest result in any region, and United Russia won 46.6 percent in 2011 parliamentary elections. A recent survey found that Mr. Sobyanin led his nearest competitor, the former mayor, Yuri M. Luzhkov, by more than 40 points. Though these favorable conditions virtually assure Mr. Sobyanin of victory, the analyst Stanislav Belkovsky told Dozhd, an online news channel, the decision to speed up the race shows that the authorities recognize that they have new political vulnerabilities: that elections are necessary to legitimize leaders" standing and that they can no longer expect growing support in Moscow. "Let them call the elections for September if they want, but these two trends are not going away," he said. Asked about Mr. Sobyanin's re-election campaign, he predicted a message "à la Leonid Brezhnev: Life is good, and it will be even better."