MOSCOW, JUNE 25 -- Boris Yeltsin, president of the Soviet Russian republic, said today that he plans to slash his republic's payments to the Soviet national budget by at least half and to establish a new system of "sovereign banks" independent of central control.

Speaking in an interview on Soviet television, Yeltsin also criticized Soviet President Mikhail Gorbachev for "continued half-measures" and failing to carry through on a "genuinely radical" economic reform program. Yeltsin said that Gorbachev had "built a bridge halfway and stopped there."

Yelstin's comments added to the political criticism that has swirled around Gorbachev during the past week. The Soviet leader was attacked from the other direction, by conservative party members, during a conference of the newly founded Russian Communist Party last week, and there are now rumors that the Moscow party leadership is considering rescheduling the 28th national Party Congress, the party's supreme governing body, from next week to September.

Estonian television reported tonight that party ideology chief Vadim Medvedev called officials in the Estonian Communist Party and said that such a postponement was possible.

According to the official Estonian news service, Medvedev said that the reason would be the "harvest that had started in southern regions of the Soviet Union." The report said Medvedev had told the Estonians that Russian and Ukrainian Communists were asking for a delay.

A party spokesman who asked not to be identified said there were "serious thoughts" about putting off the congress. The party's policy-making Central Committee is planning to meet at the end of the week, and such a decision would likely be made there.

Other Communist Party sources, including those reached in the Baltic republics, said they had not heard such rumors. "I have my ticket for Moscow in a few days and a reservation at the Hotel Rossiya. I don't expect I'll have to change my plans," said Vladislav Shved, a leader of the minority wing of the Lithuanian Communist Party, which is still linked to Moscow.

Whether or not he postpones the congress, Gorbachev faces a political dilemma in dealing with the sharply divided party. Some of his allies who support radical economic and political reform are threatening to quit the party if fundamental policy changes are not made, while countless conservatives, especially Old Guard regional party secretaries and military leaders, have charged Gorbachev with abandoning the principles of socialism.

Yeltsin, for his part, said he may suspend his party membership after the congress in order to represent "all parties" in the Russian republic. The new leader of the republic's party organization, Ivan Polozkov of Krasnodar, is one of the leading conservative critics of both Gorbachev and Yeltsin.

Ever since Yeltsin's dismissal from the top Communist Party leadership in late 1987, he and Gorbachev have been at odds, both politically and personally. After Yeltsin's election to the Russian presidency last month, however, the two seemed to have come to a tacit understanding that they would try to work together.

Yeltsin's insistence tonight that the Russian republic could no longer "pump money" into the Soviet budget and would transfer just 20 billion rubles, rather than 70 billion, to Moscow, was seen by some observers as a rhetorical means of laying down the gauntlet for further negotiations with Gorbachev. The Russian republic, the largest and most influential of the Soviet Union's 15 constituent republics, proclaimed its autonomy from Soviet legislation earlier this month.

Gorbachev has said he intends to work with the leaders of the 15 republics on a new federation treaty that would decentralize Soviet economic and political power.

The Lithuanian parliament will continue debating its bid for outright independence from Moscow on Tuesday when it discusses how to begin formal negotiations on secession with the Kremlin. Lithuanian Premier Kazimiera Prunskiene told an interviewer on regional television that legislators have drafted at least five proposals for a moratorium on the republic's March 11 declaration of independence.