MOSCOW, NOV. 4 -- As Soviet President Mikhail Gorbachev braces for a fresh wave of popular protests on the anniversary of the 1917 Bolshevik Revolution Wednesday, he is coming under fire from left and right for political indecisiveness.

Today, a group of radical economists, including two of Gorbachev's advisers, predicted that the Kremlin's latest economic reform package would fail. They said so much time had been lost arguing about a transition to a market economy that there was now no alternative to significant cuts in living standards.

Saturday, conservative legislators denounced Gorbachev for failing to take decisive action to prevent ethnic strife in the southwestern republic of Moldavia. Up to 10 people have died in clashes between local security forces and rival groups of Russian and pro-Romanian demonstrators.

The growing economic and ethnic strains come at a time when Kremlin leaders are preoccupied with ensuring that the Nov. 7 festivities pass peacefully. Once a sacrosanct holiday marked by military parades, Revolution Day has become a symbol of political divisions in Soviet society.

At Gorbachev's urging, the leadership of the legislature, or Supreme Soviet, last week sought to ban unofficial demonstrations in Moscow on Nov. 7. But it was overruled by the radical-controlled city council, which authorized two anti-Communist marches in addition to the traditional parade through Red Square by Soviet military units and official workers' organizations.

The Soviet army has in turn announced that it will defy a ban on military parades by the three Baltic republics, which are campaigning for independence from the Soviet Union. Hundreds of paratroops are reported to have been flown to the Estonian capital, Tallinn, to ensure security for the parade there.

The controversy over whether to mark Nov. 7 as a day of celebration or a day of mourning has temporarily overshadowed the more important debate about the future of the Soviet economy. Over the last few days, it has become clear that Gorbachev has failed to build a consensus among the Soviet Union's 15 republics on economic change.

Today's open letter to the newspaper Komsomolskaya Pravda criticizing the Soviet Union's latest economic recovery plan was signed by two senior Gorbachev advisers, Stanislav Shatalin and Nikolai Petrakov. They said that government plans for centrally administered price rises accompanied by monetary compensation for workers would lead to "hyperinflation."

Both Shatalin and Petrakov had favored a more radical scheme drafted last summer that was designed to create the foundations of a market economy in 500 days. But they loyally rallied around Gorbachev last month when he favored a more cautious hybrid program.

In their open letter, the economists said that weeks of hesitation over which plan to adopt had led to a further deterioration of the economy and the loss of popular confidence in the authorities. They said the government's latest promises to slash the budget deficit by three-quarters by the beginning of next year were "completely unrealistic."

Conceding that the 500-day plan was no longer workable in its original form, the economists predicted that "harsher" measures would be necessary to stabilize the economy once the government's plan was seen to fail. The 500-day plan sought to avoid cuts in living standards by soaking up excess rubles through a massive sale of state assets.

Evidence of growing political pressures on Gorbachev came at a weekend meeting of the Soyuz group of legislators, whose main aim is the preservation of the Soviet Union in its present form. The group issued a statement accusing Kremlin leaders of "opportunism and desertion."

The official news agency Tass said the lawmakers called on Gorbachev to take "vigorous actions to protect the constitutional rights of Soviet citizens" in Moldavia and other ethnic trouble spots. It said they threatened to raise the "problem of confidence in the president" at an emergency meeting of the Congress of People's Deputies, the supreme legislative body.