KIEV -- Ukraine's Communists and their allies declared war on President Leonid Kuchma's reforms Friday after big price increases and called for mass protests on next week's anniversary of the Bolshevik revolution.


Leftists at a session of parliament that was called to discuss the price rises marched into the chamber with Soviet flags three days ahead of the anniversary. Speakers launched fierce attacks on the market reforms backed by the International Monetary Fund.


"These actions have been undertaken by bandits from the government," said Socialist Anatoly Marchenko.


"This is the outcome of policies directed against our people and controlled completely by the IMF," echoed Georgy Naida, a communist.


Parliament's Socialist chairman, Olexander Moroz -- the second figure in Ukraine's state structures -- cut off the debate after an hour, pending a report from government ministers. But he pledged to rescind any measure deemed anti-constitutional.


"The actions of the government are destroying the budget and production. They are clearly an error and have nothing in common with the economic conceptions approved by the parliament or those promoted by the president," Moroz said.


"I have the constitutional right to rescind government laws. If I come to the conclusion that this will help the situation, I will rescind any measure on freeing prices."


Last month parliament gave grudging approval to Kuchma's reform plan, which calls for cuts in government expenditure and sharp reductions in inflation and the budget deficit.


In another development, leaders of Ukraine's parliament agreed Friday to discuss the former Soviet republic's signing of a key nuclear disarmament treaty.


The announcement by the assembly, which for three years refused to place the issue on its agenda, follows lobbying by the international community.


Ukraine inherited the world's third largest nuclear arsenal when the Soviet Union collapsed in 1991. It agreed last January to dismantle its nuclear weapons, but resisted pressure to become signatory to the Nuclear Non-Proliferation Treaty. Kuchma has pledged to steer the treaty through parliament.


Many lawmakers are pressing for increased international aid and a number of security guarantees before signing the nuclear agreement.


Kuchma's economic program, the first comprehensive reform document since independence in 1991, was worked out in conjunction with the IMF. The fund last week approved an initial credit of $371 million -- the first of a series of tranches intended to boost market reforms in post-socialist Eastern Europe.


But deputies were incensed by price rises for public utilities and transport which have hit Ukrainians whose average monthly earnings remain at about 1 million karbovanets, or $10. Many workers have not been paid for months.


The cost of a ride on the Kiev underground leapt this week from 200 to 1,500 karbovanets. Electricity prices climbed about fivefold and rents for state flats tenfold.