OREKHOVO-ZUEVO, Russia – Anatoly and Maya Tunikov don’t know how they’ll survive. Once factory workers in this industrial suburb of Moscow, the retired couple live on a combined pension of about 4,200 rubles ($150) a month.

They used to receive a wide range of government benefits, including free medication, free public transportation, and housing subsidies. But under Kremlin-sponsored social reforms that cut off assistance to millions of Russians as of January 1, all of those benefits have been replaced with cash payments of only 400 rubles ($14) a month. “We haven’t even received that,” Mr. Tunikov, 64, said with a bitter laugh. The couple expects their housing costs alone to double to nearly 3,000 rubles ($107) a month, leaving precious little for food, medicine, and other essentials.

“I don’t understand how this can be happening,” Mrs. Tunikov, 65, said. “Pensioners like us worked all of our lives to build this country and now we’ve been completely betrayed.”

As a result, the Tunikovs, once ardent supporters of President Putin, joined more than 3,000 other protesters here yesterday in the latest in a wave of antigovernment rallies sweeping across Russia.

In what some are already calling “the Babushka Revolution,” after the Russian word for grandmother, Mr. Putin is facing an onslaught of public anger unprecedented in his five years in office.

Carrying signs reading “Down with Putin” and “Give us back our benefits,” yesterday’s protesters cheered as opposition politicians called on the president and government to resign.

“How are people supposed to live on the pittance the government is giving them?” the deputy head of the Communist Party’s Moscow chapter, Konstantin Cheremisov, told the crowd. “This law is driving pensioners into the grave.”

Local officials trying to defend the reforms were repeatedly heckled.

“You have to pay for these services, for public transportation, for water, for electricity, or we won’t be able to provide them,” the mayor of Orekhovo-Zuevo, Vasily Kudinov, said, over the shouts of grey-haired protesters.

More than a quarter of Russia’s 144 million people are losing benefits under the reform plan, including retirees, soldiers, veterans, police officers, students, the disabled, Chernobyl cleanup workers, and victims of Stalinist repression. The benefits have been replaced with monthly cash stipends ranging from 150 rubles ($5) to 1,550 rubles ($55).

Furious pensioners have been at the fore of demonstrations across Russia since the beginning of last week, with thousands rallying in cities from Siberia to Mr. Putin’s hometown of St. Petersburg, where more than 10,000 protested on the weekend. Protesters have repeatedly disrupted traffic, including blocking roads to the country’s main airports. In some cases, pensioners have reacted violently to the loss of their benefits. In a town in the south, an elderly disabled passenger, after being asked to pay a fare, used his crutches to pummel a bus conductor. Another town registered more than 40 assaults on bus and tram drivers by outraged pensioners in only three days.

Police have started to crack down, setting up security cordons to prevent demonstrations and arresting some protesters for taking part in unauthorized rallies. But demonstrations continue and protests are expected to surge when people start receiving January utility bills, which, without government subsidies, will rise significantly.

Also, young people are expected to join the pensioners in February, when discounted transit fees for students are to be eliminated and student housing is to become more expensive. Organizers are planning a day of nationwide protests for February 12.

On Tuesday, the Communist Party leader, Gennady Zyuganov, raised the rhetoric to new levels, comparing the reform to the Beslan massacre in September, in which more than 350 people, scores of the children, were killed when Russian forces stormed a school held by Chechen separatists.

“This law is immoral, base, and vile,” Mr. Zyuganov told Moscow Echo radio. “This government must be sacked. It couldn’t cope with Beslan … and now it is creating a social Beslan. In a country where citizens are dying by the millions they are putting this plastic bag over the heads of all pensioners.”

The Communists, the largest political opposition group, are pushing for a motion of no confidence in the government but are unlikely to collect enough signatures to force a vote in the State Duma, the lower house of Parliament, which is dominated by the pro-Putin United Russia party. Mr. Putin has defended the program, insisting it is needed to sweep away remnants of the Soviet system that Russia can no longer afford. But in the wake of the protests, he also criticized his own Cabinet and regional leaders for failing to implement the reform plan properly and ordered the government to increase the average monthly pension by at least 200 rubles ($7) as of March 1.

Authorities have started making concessions, with officials in wealthy cities, including St. Petersburg and Moscow, pledging to subsidize travel passes or restore free rides on public transport. But with social unrest expected to rise, speculation is rife that Mr. Putin may fire top ministers, or even dismiss the entire Cabinet, to deflect criticism.

State-controlled television topped newscasts yesterday with footage of officials defending the reforms. The minister of health and social development, Mikhail Zurabov, said the government would not reverse course because the country’s infrastructure is degenerating without financial support. “We can herd this problem into a corner, but we’ll face the same situation in a year or two,” Mr. Zurabov said.

The finance minister, Alexei Kudrin, went on the offensive, accusing protesters of representing a loud but tiny minority.

“One percent of benefit recipients actively took part in the protests,” he said. “We are on a very dangerous line. In wanting to be heard, they are disrupting transport, blockading roads, dealing an economic blow to regions, and harming those who cannot be reached by ambulances.”

Observers say the scale of the demonstrations has stunned the Kremlin. Rising living standards due to steady economic growth had made Mr. Putin widely popular, and pensioners were among his core constituency. In moves widely criticized as undemocratic, Mr. Putin has also managed in the past few years to bring the television media, Parliament, and regional leaders largely under presidential control.

Some opposition leaders are hopeful that the protests could lead to a democratic resurgence in Russia along the lines of Ukraine’s Orange Revolution.

“What I think they were counting on was that people would keep quiet. They reckoned everybody would swallow it as usual and that nothing would happen,” an independent member of the Duma, Vladimir Ryzhkov, said.