Until the adoption of the 1925 constitution, the fairness of the electoral process was determined by Congress itself. Because of widespread abuses engendered by the system, the constitutional reformers of the time created the Electoral Certification Tribunal (Tribunal de Certificación Electoral--TCE), drawn by lots from a group of distinguished public figures, primarily jurists, who would evaluate the integrity of the electoral process and rule on particular challenges. The 1980 constitution preserves the TCE, specifying that its members include three ministers or former ministers of the Supreme Court chosen by the Supreme Court through a secret ballot, a lawyer also elected by the Supreme Court, and a former president of the Senate or Chamber of Deputies who has held that post for no fewer than three years. The TCE's duties and responsibilities are defined by an organic constitutional law (Law 18,460).

Data as of March 1994