Mayor Marion Barry has asked the D.C. City Council to rename the two blocks of Massachusetts Ave. NW in front of the South African Embassy after black South African activists Nelson and Winnie Mandela.

"The renaming . . . will send a clear message to the world that those of us who live in our nation's capital fully support the efforts to free Nelson and Winnie Mandela and all black South Africans," Barry said.

Nelson Mandela has been imprisoned for 23 years for his political activities. His wife, Winnie Mandela, has been "banned," which means she cannot be quoted, attend public meetings or be with more than one person at a time.

Last year Barry and D.C. City Council Chairman David A. Clarke opposed proposals in Congress to rename the block in front of the Soviet Embassy after Soviet dissident Andrei Sakharov, citing a District law that prohibits naming streets for persons until at least two years after their death.

At the time, Pauline Schneider, Barry's director of intergovernmental relations, testified that the city had resisted pressure to break the rules for special cases. She said that such attempts to put pressure on a foreign government could cause a hardening of its position.

Congress decided to designate the property under the Soviet Embassy on 16th Street NW as "Andrei Sakharov Plaza."

Schneider said the difference this time is that it is a local initiative, not something Congress is imposing on the city. "The mayor feels strongly about what is happening in South Africa," she said.