Sen. Edward Kennedy (D-Mass.) yesterday denounced the plebiscite scheduled by Chile's military government as a fraud and called for the U.S. government "to disassociate itself both publicly and privately from the Pinochet regime."

In the House of Representatives, Tom Harkin (D-Iowa) and 39 other members signed a letter to Gen. Augusto Pinochet calling the plebiscite a "transparenty fraudulent . . . affront" to the Chilean people.

Kennedy called on the State Department to "reject the upcoming plebiscite as a farce and the draft constitution as a fraud and state our view that we will accept nothing less than an end to human rights abuses and the restoration of democracy."

Until now, the State Department has limited itself to declaring that "our preference for democratic processes and board free participation in an electoral process is well known."

In a similar plebiscite posed by Pinochet in 1978 following a condemnation by the U.N. General Assembly, the State Department strongly denounced the exercise but only after it was completed.

Kennedy called for the U.S. support of "actions in both the Organization of American States and the United Nations to condemn the proposed constitution and the plebiscite as counter to the international obligations of the American Convention on Human Rights and the International Covenant on Civil and Political Rights."