MOSCOW, NOV. 16 -- President Mikhail Gorbachev promised today to reshuffle the Soviet government and military leaderships in an attempt to win back public confidence, but came under fire for political indecisiveness from both left and right.

Addressing an emergency session of the federal legislature, or Supreme Soviet, called to debate the state of the nation, Gorbachev accused his opponents of seeking to exploit the deepening economic and social crisis in order to launch "a real struggle for power." He called on the country's restless republics to respect a political truce with the Kremlin until the negotiation of a new union treaty clarifying the precise division of powers in a reformed Soviet federation.

The president's 70-minute speech failed to satisfy many leaders of the republics who had been summoned to Moscow to attend the session of the Supreme Soviet. The session, which will continue over the weekend, is taking place in a tense atmosphere after deputies threw out their previous agenda on Wednesday after complaining about a paralysis of political power.

Russian President Boris Yeltsin, who is widely regarded as Gorbachev's most prominent political rival, called for the immediate formation of an "extraordinary anti-crisis committee" made up of representatives of all 15 republics. Yeltsin also demanded the dismissal of the federal government headed by Prime Minister Nikolai Ryzhkov, which he described as the "major power base for the conservative forces in this country."

"The crisis we are experiencing today is a crisis of a totalitarian state, which is reflected in the paralysis of power," said the strapping, silver-haired Yeltsin. "The people's patience is ending and an explosion could occur at any time."

Gorbachev, who leaves Sunday for a brief visit to Rome before the 34-nation European summit in Paris, made clear that he has no intention of sacrificing Ryzkhov at this point. He said the 61-year-old prime minister agreed that it is necessary to broaden the social base of the government to include "politicians and experts who are most popular and enjoy wide social support."

The president linked his revelation of imminent "personnel changes at the highest level of command in the armed forces" to promises to act decisively to defend the army from "slanderous" attacks by opposition groups. He gave no details about the proposed changes, but an unofficial servicemen's union said recently that Defense Minister Dmitri Yazov is likely to be replaced by one of his deputies, Army Gen. Petr Lushev.

Since becoming defense minister in 1987, Yazov has gained a reputation for political loyalty to Gorbachev, but he has generally been rated as a poor administrator and a bluff officer of the old school, rather than an innovator.

Further political pressure on Gorbachev came from Communist Party hard-liners who are demanding a halt to his perestroika reform program. The leader of the Russian Communist Party, Ivan Polozkov, called on the president to take the "strongest possible measures" to restore law and order in the country, adding that continuing inactivity by the authorities "could lead us to reconsider our attitude to the center."

"Today we are faced with the fact that socialist perestroika is being transformed into something else," wrote Polozkov in the newspaper Sovietskaya Rossiya. He argued that Gorbachev's reforms have allowed speculators to flourish, weakened the Soviet defense industry and left the country without military allies following the collapse of the Soviet-led Warsaw Pact.

Weighed down by complaints from both sides, Gorbachev has sought to occupy the diminishing middle ground in Soviet politics. In his speech today, he insisted that he would stick to his policy of gradual reform, suggesting that rapid agreement on a new union treaty could resolve the present "legislative war" between the federal Supreme Soviet and the legislatures of the republics.

But while the president provided a blunt assessment of the country's problems -- including worsening food shortages, a breakdown in law and order and the danger of economic and political "Balkanization" -- he offered no new solutions. His position disappointed many deputies who had been hoping for some kind of decisive action.

"The president did not provide us with any clear-cut program for how to get out of the present crisis. The time of political improvisations and empty declarations has gone for good. Now is the time for extraordinary action," said Anatoly Sobchak, the mayor of Leningrad, which introduced full-scale rationing this week for the first time since it was besieged by the Nazis in 1941-44.

Echoing recent comments by leading Soviet commentators, Sobchak said Gorbachev was faced with a clear choice between speeding up the transition to democracy and reverting to authoritarian rule. The mayor said it would be possible to impose direct presidential rule over the entire territory of the Soviet Union only with the help of the "army, bayonets and punitive agencies such as the KGB {security police} and Interior Ministry."

"Comrades, I think you all understand that this option has no future. It will lead only to civil war and bloodshed and runs against the political and moral principles of the president himself," he said.

Many radical politicians fear that, unless Gorbachev moves rapidly to create a coalition government of national unity, the economic situation could deteriorate until the authoritarian option would be the only way out. Political divisions within the armed forces make most observers here skeptical about recent rumors about a surprise military coup against Gorbachev, even though such a possibility cannot entirely be ruled out.

Most of today's Supreme Soviet session was taken up by speeches from the leaders of the 15 republics, many of whom supported Yeltsin's criticisms of the central authorities. Vitold Fokin, the newly appointed Communist prime minister of the Ukraine, blamed the economic and political crisis on the "inconsistent and at times illogical policy" of the federal leadership.

The debate made clear that at least five republics -- the three Baltic states, Georgia and Armenia -- will refuse to sign a new union treaty as urged by Gorbachev. The Ukraine and Moldavia are wavering under pressure from influential nationalist opposition groups, while Russia is demanding a much greater degree of decentralization than the Kremlin so far is prepared to concede.

In his speech, Gorbachev complained about the lack of proper mechanisms to enforce presidential decisions. He denounced what he described as a "well-orchestrated campaign in this country to discredit me," while conceding that some of his decisions had been either late or ineffective.

"For some reason, every decree that I issue is first discussed to see whether it should be carried out or not. For heaven's sake, if they are not carried out, nothing is going to get done. I think those officials who block my decrees should be simply sacked," said the president, raising his voice in indignation.

Since his election to the new executive post of president in March, Gorbachev has issued dozens of decrees on subjects that ranged from disarming vigilante groups to protecting state monuments. After provoking an initial splash in the press, many of the decrees simply have been forgotten.