In accordance with the constitution that came into force in 1981, the National Congress is composed of a Senate and a Chamber of Deputies. The Senate has 47 members (38 elected and 9 appointed) who serve an eight year term. The Chamber of Deputies has 120 members who are directly elected for four years.
As laid down in the Constitution, a plesbicite was held in October 1988 to determine whether the rule of the military dictatorship under General Pinochet shoul be extended (governing since 1973). Nearly 55 percent voted against the continuation of the military regime. This led to free presidential elections in December 1989, in which Patricio Alwyn Azocar of the Christian Democratic Party (PDC) was elected, supported by a 17-party coalition.