The Supreme Soviet of the Union of Soviet Socialist Republics () was, beginning in 1936, the most authoritative legislative body of the Union of Soviet Socialist Republics (USSR), and the only one with the power to approve constitutional amendments. Prior to 1936, the Congress of Soviets was the supreme legislative body. During 1989–1991 a similar, but not identical structure was the supreme legislative body. The Supreme Soviet elected the USSR's collective head of state, the Presidium; and appointed the Council of Ministers, the Supreme Court, and the Procurator General of the USSR. By the Soviet constitutions of 1936 and 1977, the Supreme Soviet was defined as the highest organ of state power in the Soviet Union and was imbued with great lawmaking powers. In practice, however, it was a pseudo-parliament that did little more than rubber-stamp decisions already made by the USSR's executive organs and the CPSU — always by unanimous consent — and listen to the General Secretary's speeches. This was in accordance with the Stalinist CPSU's principle of democratic centralism and became the norm for other Communist legislatures. Structure The Supreme Soviet was composed of two chambers, each with equal legislative powers, with members elected for four-year terms: The Soviet of the Union, elected on the basis of the population with one deputy for every 300,000 people in the Soviet federation. The Soviet of Nationalities, which represented the ethnic populations as units, with members elected on the basis of 32 deputies from each union republic, 11 from each autonomous republic, five from each autonomous oblast (region), and one from each autonomous okrug (district). The administrative units of the same type would send the same number of members regardless of their size or population. The Supreme Soviet convened twice a year, usually for less than a week. For the rest of the year, the Presidium performed its ordinary functions. Often, the CPSU bypassed the Supreme Soviet altogether and had major laws enacted as Presidium decrees. Nominally, if such decrees were not ratified by the Supreme Soviet at its next session, they were considered revoked. In practice, however, the principle of democratic centralism rendered the process of ratifying Presidium decrees a mere formality. In some cases, even this formality was not observed. After 1989 it consisted of 542 deputies (divided into two 271 chambers) decreased from a previous 1,500. The meetings of the body were also more frequent, from six