MOSCOW, FEB. 5 -- Soviet President Mikhail Gorbachev today declared invalid a republic-wide non-binding ballot on independence that Lithuania plans to hold Saturday.

Gorbachev said the poll is "without legal foundation" and is an attempt by Lithuania's leadership "to generate support for their separatist aims." The decree nullifying the non-binding vote is certain to intensify the confrontation between the Kremlin and Lithuania's pro-independence government.

Lithuanian President Vytautas Landsbergis rejected Gorbachev's decree, saying it "reflects an old tradition of the Soviet Union, according to which law and government arise not from the will of the people, expressed by a free vote, but are formed instead by the decrees of autocratic rulers."

Gorbachev's decree referred vaguely to preventing the poll, but there was no indication whether Moscow plans to block it. Landsbergis said such action by the Kremlin would constitute "impermissible political interference in the matters of the sovereign Lithuanian state."

{In Washington, President Bush expressed confidence Tuesday that the Soviet Union "will never go back, no matter what happens, to the totalitarian, closed society days of the Cold War," the Associated Press reported.

{Asked at a news conference about reports that Gorbachev is, in effect, sharing power with the military and unable to make decisions on his own, Bush replied, "Well, he is still in charge, and he is still the president of the Soviet Union." But he added, "He has enormous problems at home. It's a very troubling situation inside the Soviet Union right now."}

Landsbergis has rejected Gorbachev's demand that Lithuania hold a referendum in order to begin legal proceedings for secession from the Soviet Union. Landsbergis contends that Moscow's annexation of the Baltic states in 1940 was illegal and that the parliament's declaration last March reasserting independence is legally binding.

Three weeks ago Soviet troops stormed the Lithuanian republic's television tower in Vilnius, the capital, killing 14 people and injuring more than 200. Since then, the parliament has been surrounded by huge concrete barricades and Landsbergis has left the building only once, for fear that troops will arrest him and dissolve the legislature.

Gorbachev's decree said "the poll and the attempt to call it a plebiscite on the future of the Lithuanian state are legally invalid," according to the official news agency Tass. The poll, it said, "cannot be seen as anything other than an attempt to block the carrying out in the republic {of} a national referendum on the question of preserving the Soviet Union."

The Kremlin plans to hold a nationwide referendum March 17 asking voters whether or not they favor the preservation of the present union, but Lithuania, Estonia, Georgia and Armenia have announced they will not participate.

Gorbachev clearly feels that the Lithuanian poll is intended both to undermine the national referendum and to show just how strong sentiment in the republic is for independence.

The Lithuanian poll, which is expected to win overwhelming support among ethnic Lithuanians and to a lesser extent among the minority Russian-speaking population, will ask: "Do you agree that the Lithuanian state should be an independent, democratic republic?"

The Estonians and Latvians plan to conduct similar independence polls in the coming weeks. Moscow has said it has been acting to protect the rights of ethnic minorities in the region, but since the violence this month in the Baltics, polls have shown that support for independence even among the Russian-speaking populations has increased dramatically.

Gorbachev announced last week that he was sending Kremlin delegations to all three Baltic states for discussions with their leaders, but his general position toward the republics has softened little.

Col. Viktor Alksnis, outspoken leader of the hard-line parliamentary faction Soyuz, said in an interview, "Gorbachev finally woke up and realized his policies were leading to the collapse of the Soviet state."

Alksnis, who supports an extended period of authoritarian rule before establishment of democracy, said Gorbachev had originally agreed to a plan in which he would step in eventually and declare direct presidential rule in the Baltic states.

"But he didn't have the courage to finish the job in Vilnius," Alksnis said. "He was like a surgeon who leaves halfway through the operation and the patient is left there bleeding on the table."

Landsbergis told reporters in Vilnius that the West's reaction to the deaths there Jan. 13 at the hands of Soviet authorities "woke up" the Soviet leadership to the dangers of a crackdown.

"The West, which is so fond of Gorbachev, could help him by helping the democratic forces to create a counterbalance to the right," Landsbergis said.

Some of Gorbachev's colleagues no longer make any pretense of the Soviet leadership's turn to more authoritarian tactics. Yuri Prokofiev, head of the Moscow Communist Party, said this week that he would "not be afraid" to call Chile a model for developments here.

After overthrowing the socialist government of Salvador Allende in 1973, Gen. Augusto Pinochet established an authoritarian government and, in Prokofiev's words, "the infrastructure for a market." Pinochet ruled for 16 years until yielding power last year in democratic elections.

In another indication that Gorbachev endorsed the crackdown in Lithuania and Latvia, he promoted his new, hard-line interior minister, Boris Pugo, from lieutenant general to colonel general. Special Black Beret troops under Pugo's ultimate authority were responsible for four deaths earlier this month when they raided the city police headquarters in Riga, capital of Latvia.

The Interior Ministry in Moscow announced today that it will increase by at least 50 percent the number of its new joint police-military patrols. The four-man patrols, which have been denounced by pro-democracy politicians as a sign of "creeping military rule," are to be increased from 1,740 to 2,636 nationwide.

Interior Ministry spokesman Vladimir Yanchenkov said that the patrols, which began Feb. 1, have detained 5,000 people so far, mainly for theft and street crimes. Although Pugo has said the patrols would not be used for political purposes, liberals such as Moscow Deputy Mayor Sergei Stankevich are concerned that the new structures could be used later to carry out a national crackdown.

The Interior Ministry announced that under a decree from Gorbachev on Monday, it will create a new "main directorate" that will work with the KGB secret police to fight organized crime and investigate "criminal activities of groups that commit the most dangerous crimes and have inter-republic and international connections."

Police are also conducting a criminal investigation of Artyom Tarasov, probably the Soviet Union's best-known entrepreneur. Tarasov, who runs the foreign trade company Source, is likely to be charged with currency violations, according to the news program "Vremya."

Liberal publications, however, have defended Tarasov, saying he has become a target of investigation mainly because he personifies the growth of private enterprise here and also because he recently embarrassed Gorbachev, saying that the Soviet leader planned to sell the Kurile Islands to Japan for billions of dollars. Gorbachev denied the report and said he would sue Tarasov.