The National Assembly, a unicameral legislature, is the only legislative body of the central government, but legislative initiative has been extended to several other governmental organs. In practice the State Council appears to be the most powerful organ of government as well as the principal initiator of legislative matters. The assembly, which meets only three times each year in short sessions, would appear to have more form than substance in the actual governmental affairs of the country. It would seem to be impossible for anyone to become a member of the assembly or of the State Council without prior approval of the BKP (see ch. 9). The assembly's 400 members represent voting districts of equal numbers of inhabitants per delegate. The term of office is five years. This was another innovation in that the BKP hierarchy decided that party congresses would be held every five years instead of four and, therefore, elections to the National Assembly should be changed in the same manner. In the exercise of its functions, the National Assembly can dissolve itself, and in emergency situations it may extend its term. The manner in which the National Assembly operates, that is, the infrequency and brevity of sessions, makes it imperative for permanent commissions, in addition to the State Council, to carry on the multifarious functions of the assembly. In 1971 there were twelve permanent commissions, half of which had overlapping functions with various ministries. The constitution does not specify how many permanent or interim commissions the assembly should appoint but leaves such matters of organization to the assembly itself. Local Government Territorially, Bulgaria is divided into twenty-eight districts (_okruzi_; sing., _okrug_), about 200 municipalities, and about 5,500 villages. The municipalities, if size warrants, are divided into urban constituencies (_rayoni_; sing., _rayon_), whereas villages are usually grouped together to form rural constituencies known as _obshtini_ (sing., _obshtina_). Since 1959 the number of districts has remained constant at twenty-eight, which includes one for the city of Sofia. The number of urban and rural constituencies, on the other hand, changes frequently as the population increases and as people move from the countryside to the cities or move from cities to suburban areas. Districts and urban and rural constituencies are governed on the local level by people's councils, and in the 1971 elections there were almost 1,200 such councils with a total of more than 53,000 elected officials.