Foreign Minister Eduard Shevardnadze resigned because he believed his influence was waning and felt that Soviet policy abroad was being undercut at home, an aide said Saturday.

Leonid Kravchenko, head of the State Committee for Radio and Television, meanwhile denied television journalists' assertion that he prohibited them from broadcasting a program about Shevardnadze late Friday.But Teymuraz Stepanov, a senior aide to Shevardnadze, accused Soviet state-run media of imposing a news blackout on coverage involving the white-haired minister since his stunning Dec. 20 resignation announcement.

The comments by Stepanov in the Komsomolskaya Pravda newspaper provided the first on-the-record details of Shevardnadze's decision from a close associate.

"Since his resignation a strange situation has developed: In the West there has been a storm, but here in our country we have a sort of silence zone," Stepanov said.

In his dramatic speech to the Congress of People's Deputies, Shevardnadze warned that right-wing forces were pushing the country back toward dictatorship.

Reporters for the weekly news program "Vzglyad" held a protest Friday at the Union of Cinema Workers, charging Kravchenko had said they might be fired if the popular show proceeded with plans to air interviews with Stepanov and another Shevardnadze aide, Sergei Tarasenko.

Stepanov said he wanted to speak on Vzglyad to refute "foolish" explanations for Shevardnadze's resignation.

"There has been a gradual narrowing of the domestic basis that had supported us in conducting the foreign policy associated with the name of Shevardnadze," Stepanov said in the newspaper interview. "The minister has exhausted all his reserves, and he is unable to exert any influence on the situation."

Stepanov, in speaking of a "gradual narrowing," appeared to be referring to a reduction of domestic support for Shevardnadze's foreign policy because of current conservative trends beyond the foreign minister's control.

Stepanov rejected claims Shevardnadze quit in an emotional burst of frustration, saying he had been thinking of resigning for a year.

Alexander Lyubinov, one of Vzglyad's three well-known anchormen, told Komsomolskaya Pravda: "Yes, we wanted to invite Stepanov and Terasenko, but Kravchenko . . . did not allow us to do this. Starting from Monday we tried to persuade him, but all the talks proved useless. It is clear that this was done for political reasons."

The program did not run in its usual midnight time slot Friday night.

In a separate interview with the independent Interfax news service, Lyubinov, who is also a deputy in the Russian Federation's Parliament, said, "We are deeply concerned about the chain of resignations in the country's leadership."

Kravchenko, who headed the official Tass news agency until becoming the TV czar last month, denied he had prohibited the Shevardnadze aides' appearance, saying only he "advised against" extending an invitation to the 62-year-old Georgian himself.

Lyubinov said he had "information that Kravchenko discussed the matter with Mikhail Gorbachev," but the newsman did not elaborate.

In an interview from the trip later run on Vzglyad, Shevardnadze said he almost resigned in April 1988 when he and other members of the Communist Party's ruling Politburo were accused of ordering the use of force against a peaceful protest in Tbilisi, capital of his native Georgia. Twenty people were killed in the crackdown.