LOS ANGELES (AP) _ Actress Jane Fonda and Mayor Tom Bradley said Tuesday they are asking Soviet leader Mikhail Gorbachev to free a critically ill Soviet Jew who has been trying to emigrate to Israel for 13 years.

Ida Nudel, 54, an economist and organizer of the Soviet Jewry movement, was ordered banished to Siberia for four years in 1978 after being convicted of what the Soviet government called ''malicious hooliganism'' for hanging posters from the balcony of her Moscow apartment demanding an exit visa to join her sister, Elena Fridman, in Israel.

Upon Ms. Nudel's return, authorities refused her permission to live in Moscow. She now lives in Bendery in Soviet Moldavia, about 1,000 miles southwest of Moscow.

''Ida Nudel is a woman whose case has come to symbolize the struggle of Jewish citizens in the Soviet Union for human rights and religious freedom,'' Ms. Fonda said at a City Hall news conference. ''She has been harassed for celebrating the high holy days and threatened for practicing her religion.''

In 1972, Ms. Nudel and her sister's family applied for exit visas. Her relatives received visas, but Ms. Nudel did not, and the reasons for the refusal are unclear, said Steve Rivers, Ms. Fonda's spokesman.

Ms. Nudel has been suffering from a critical illness and unable to obtain medical care from Soviet authorities, Ms. Fonda said.