The Kremlin has been shaken by the recent emergence of the protest movement among middle-class Muscovites, who only a few months ago were considered to be largely politically inert. Tens of thousands have braved sub-zero temperatures, occasional arrests, and the loss of weekend shopping time to attend several boisterous protests against Mr. Putin's rule.

On Sunday, amid slush-clogged streets and a steady snow, a carnival atmosphere prevailed, with vendors handing out free hot tea and pancakes to mark the last day before Orthodox Lent. The protest was called the Big White Circle after the movement's color, and demonstrators arrived decked out in full length white furs and huge white hats. Long lines of people waved unfurled rolls of paper towels, while cars drove along the road, the Garden Ring, honking furiously displaying their own white flags and banners.

Yet despite the upbeat mood, few had any illusions about the results of the election next Sunday.

"I'm afraid that the results of the election have already been determined and Putin will win," said Olga Abashkina, 54, a teacher. "This will be the official result, though it is not clear if it will actually be the case."

That eventuality has hung over the protest movement almost since it began in December over allegations of fraud in parliamentary elections. Though dissatisfaction with Mr. Putin in Moscow and several other large cities is high, he still enjoys broad support among rural and blue-collar voters. Even without blatant fraud, most polls suggest that Mr. Putin could win over 50 percent of the vote.

Most demonstrators on Sunday could offer only vague speculation about the future of the protest movement after that. Few said they believed recent promises by Mr. Putin and his government to push for more democratic reform.

"A chef who has cooked meat his whole life will not suddenly become a vegetarian," said Aleksei Yalyshev, 28 an economist.

Despite a few sparse patches, protesters filled most of the length of the 10-mile highway, suggesting that enthusiasm for the movement was not on the wane as Kremlin officials and Mr. Putin's supporters have insisted. The police said that 11,000 people attended the event, though that number was impossible to independently confirm. Protest organizers said they needed over 30,000 people to create a human chain the complete distance around the highway.

The police said that they detained several protesters for trying to hold another rally near the Kremlin, though no other disturbances were reported.

Most demonstrators expressed optimism that many would continue to clog Moscow's streets and squares to register their dissatisfaction should Mr. Putin win next week.

"We expect for Putin to win, but it will be his last victory," said Vakhtan Dzhariani, 52, a businessman. "I don't think he will last out his next term, because the situation in the country will develop quickly and not to his advantage. The country has woken up."

Mr. Dzhariani and others were less sure, however, about what it would take for Mr. Putin to leave power.