Leftist opposition leaders drew about 200 activists to a Moscow rally on Monday and reached out to blue-collar workers to try to expand the protest movement against Russian Prime Minister Vladimir Putin.
Left Front leader Sergei Udaltsov told the crowd on a snowy square that only by staying united can they hope to pose a serious challenge to Putin, who is aiming to win a third presidential term in March.
In addition to demanding free elections and political reforms, he said the protesters should defend the rights of workers and demand stronger social protection for Russia's poor.
The activists, some of whom waved red Communist flags, dislike some of the liberal and pro-business leaders at the forefront of the opposition.
Other speakers urged the activists to visit factories around the country and persuade workers to join a mass protest on Feb. 4. Most of the tens of thousands of Russians who attended protests in December after a disputed election were middle-class professionals.
The demonstrations, the biggest Russia has seen in two decades, reflected outrage over a Dec. 4 parliamentary election in which the vote was manipulated to boost the results for Putin's party.
Putin, who served as president from 2000 to 2008, is expected to win the March vote, due to the absence of a strong challenger and the Kremlin's tight hold over the electoral system.
Udaltsov, a 34-year-old rising star in the protest movement, said a splintered opposition would allow Putin to take revenge against his opponents after the election.
"The month I was in jail may turn out to be a bed of roses for me and many others," he said. "If we are divided it might happen very quickly."
Udaltsov spent most of December in custody on charges related to past street protests. By his own count, he was detained about 30 times last year and jailed for a total of 2 1/2 months. His persistence in the face of broad police pressure has earned him new respect from the broader opposition movement.
He warned the government against using force against the protesters, whose rallies in December were peaceful.
"We who have already declared the peaceful nature of our demands, the peaceful nature of our activities, at the same time should be clear in warning the authorities: If they spill blood, this would be a signal to the whole society for a rebellion, and I don't think they will be able to escape responsibility in this case," Udaltsov said.