The plight of Jews in the Soviet Union has degenerated into a "catastrophical situation" in recent years, Yuri Stern, a Soviet dissident who recently emigrated to Israel, said yesterday.

Speaking to about 15 people over dinner at Hillel, Stern, a research worker at Moscow University until his emigration this past April, said that Jews are deprived even of those basic national rights which other minorities in the Soviet Union enjoy.

"Practically, Jews are not considered to be a part of the so-called Soviet nations," he added.

Stern said that in the past few years all Jewish institutions and organizations have been closed down and Jewish activists arrested. Soviet officials recently closed the Cultural Seminar in Leningrad, which dealt which the period of the Second Temple and related issues, because of its "anti-Soviet" studies, he added.

This October, only 300 Jews were permitted to emigrate, compared to 1000 last October and 4000 to 5000 per month two years ago, Stern said.

Another 400,000 have received invitations from relatives in Israel, the first step in being granted an exit visa, but have been refused permission to leave, he said. Since the mail is censored, those who have received the invitations have been blacklisted, he added.

After the 1967 war between Israel and her Arab neighbors, Jewish cultural life in the Soviet Union began to increase a little, Stern said. The authorities tolerated this growth for a few years but have recently cracked down, he added.

"Now Jews wish only to go away, and to receive some knowledge about their culture while they're still there," Stern said. Pressure from the West in the from of letters to Soviet and American officials, demonstrations, and any other form of publicity can help reduce jail sentences and raise emigration, he added.

A demonstration on behalf of two dissidents who face trial on charges of "anti-Soviet propaganda" for teaching Hebrew in Moscow will be held this coming Sunday at 10 a.m. at the Young Jewish Adult Center in Brookline, Stern said. Sen. Paul Tsongas (D.-Mass.) and a representative of Amnesty International will attend, he added.