The federal government exercises complete sovereignty. On 3 October 1990, the Federal Republic of Germany and the German Democratic Republic were unified in accordance with Article 23 of the Basic Law (Grundgesetz) of 23 May 1949, under which the FRG is governed and which serves as a constitution. It may be amended by a two-thirds vote of the legislature.
The bicameral legislature (the federal parliament) consists of a federal council (Bundesrat) and a federal diet (Bundestag). Members of the Bundestag are elected for four-year terms by universal, free, and secret ballot, and may be reelected; voters and candidates must be at least 18 years of age. The Bundestag had 497 voting deputies in 1987; 22 nonvoting deputies represented West Berlin. Following unification, Bundestag membership was raised to 662 deputies; as of 2003 it stood at 603. The Bundesrat, which has absolute veto power over legislation affecting the provinces (Länder), consists of 69 representatives appointed by the provincial governments according to the population of each province. Disagreements between the two chambers are handled by a conciliating committee.
The chancellor, the leader of the executive branch, is elected by a majority of the Bundestag and serves until a new Bundestag is elected or until a majority vote dismisses him. The chancellor determines and is responsible for policy, and selects the ministers who head the various administrative departments. The president, who is chief of state, performs the largely ceremonial functions of proposing the chancellor to the Bundestag, promulgating laws, formally appointing and dismissing judges and federal civil servants, and receiving foreign ambassadors. The president is elected for a five-year term by a federal convention composed of members of the Bundestag and an equal number of delegates elected by the provincial legislatures.