Protesters chanting "Russia without Putin" began marching through Moscow on Saturday in a protest seen as a test of the opposition's ability to mount a sustained challenge to President Vladimir Putin.
Several thousand demonstrators began marching under cloudy skies from the central Pushkin Square along a route that will take them close to the Kremlin in what is intended to be the first big opposition rally for three months.
Some had banners declaring "Putin is a parasite". Others wore T-shirts demanding the release of three members of the Pussy Riot punk band who were jailed after singing a profanity-laced "punk prayer" in a church.
The demonstration will indicate whether the protest movement that began nine months ago, and has at times attracted tens of thousands of people to rallies, still has momentum four months after Putin began a six-year term as president.
Although the Kremlin announced minor political reforms after the demonstrations began last December, Putin's presidential election victory in March took the sting out of the protests and the opposition remains disunited, without a clear leader.
"We are protesting against the total lawlessness, total corruption, the lack of civil freedoms, the absence of independent courts and social injustice," said Sergei Yevseyev, 35, who works for an international shipping company.
He said Putin's style of government was no longer effective more than a decade after he first became president and added: "When he first came to power we needed this toughness, but not anymore. Society has stabilized."
People were trickling slowly to Pushkin Square, the starting point, and the early signs were that the rally might not attract the 50,000 the opposition hoped for. Police were out in force although the organizers received permission for the rally.
OPPOSITION STRUGGLES FOR UNITY
The Kremlin has dismissed the protesters as a minority that does not have wide support across the country of more than 140 million.
Putin's opponents say his return to the presidency after four years as premier is a bad sign for democracy as he has already dominated Russia for 12 years. They fear his new term will be marred by political and economic stagnation.
But the opposition has struggled to unite its various groups - including nationalists, leftists and middle-class liberals - under one leader and they have no clear program beyond a common desire to oust the 59-year-old Kremlin chief.
It is the first time the opposition has tried to gather large numbers at a protest since a court jailed the three Pussy Riot members for storming into Moscow's main Russian Orthodox cathedral and protesting in front of the altar against Putin's close ties with the clergy.
Opinions polls show few Russians sympathized with the protest itself, but the severity of the band members' treatment widened divisions in society, with liberals complaining of a crackdown on dissent by the former KGB officer.
The opposition is also upset by new laws that increased protesters' fines, stiffened punishments for defamation and imposed new controls on foreign-funded campaign groups.
In another setback for the protesters, opposition deputy Gennady Gudkov was expelled from parliament on Friday on allegations of illegally continuing business activities while holding a mandate in the assembly.
"In the 100 days since Putin's return to the Kremlin we see that he has shown all the symptoms of this new political course - that is a tightening of the screws," said former Prime Minister Mikhail Kasyanov, who is now an opposition leader.
Protests were also planned in St Petersburg and in Yekaterinburg in the Ural Mountains. A rally in the Far East city of Vladivostok was much smaller than the opposition had hoped, witnesses said.