The constitution of 8 November 1960 established the president of the republic, elected for a five-year term by direct universal suffrage, as chief of state and head of the executive branch. Legislative power was invested in a 50-member unicameral National Assembly. This constitution was suspended following the military coup of 15 April 1974, when the National Assembly was also dissolved. All executive and legislative power was taken over by the Supreme Military Council, composed of army officers. The president of the Supreme Military Council was president of the council of ministers (cabinet) and head of state. Seyni Kountché held this office from 1974 to 1987. Most cabinet officers were civilians in 1987.
In 1987, a national development council was established to serve as a constituent assembly on a nonparty basis. It drafted the constitution of the Second Republic that came into force on 24 September 1989.
A national conference from July to October 1991 drafted a multiparty democratic constitution that was approved by national referendum on 26 December 1992. It established the Third Republic with a National Assembly of 83 deputies chosen by popular and competitive elections, a president likewise elected, and a prime minister elected by the Assembly. The new government with Mahamane Ousmane as its head was sworn in on 23 April 1993.
Political gridlock led to a (relatively) bloodless coup led by (then) Colonel Ibrahim Baré Maïnassara in January 1996. Within six months, the regime had drafted and submitted for national referendum a new constitution with a significantly strengthened executive. The document was approved on 12 May 1996 ushering in the short-lived Fourth Republic. In flawed elections, Baré Maïnassara declared himself winner over four other candidates on the first round, and his UNIRD party won a majority of seats in the Assembly.
Baré Maïnassara was assassinated on 9 April 1999 by his presidential guard. Major Daouda Wanké reappointed Ibrahim Assane Maiyaki as prime minister for the transition government. He then appointed a transitional cabinet consisting of 20 members, most of whom were civilian. Wanké also replaced 7 of Niger's regional military leaders. He announced that he would not run for the presidency and disqualified all military and security personnel, as well as all members of the transitional government from standing for election. Wanké named a 60-member independent national election commission to oversee the establishment of the election roles and the polling. The CRN renounced any form of remuneration during the transition period and moved to reduce by half the salaries of future members of government.
The constitution of the Fifth Republic, passed in July 1999, provided for a semi-presidential government. The president is head of state, he appoints the prime minister (head of government) from a list of three candidates proposed by the parliamentary majority. The president names all 23 cabinet ministers and other high-ranking civilian and military officials. Presidential actions must be countersigned by the prime minister. The national assembly can unseat the prime minister through a no-confidence vote. The president can dissolve the national assembly, assume emergency powers, and convene the Council of the Republic in the event of a constitutional crisis. This Fifth Republic constitution created four new bodies: the constitutional court, the superior national defense council, the council of the republic (a conflict resolution body) and the economic, social and cultural council. The Council of the Republic was created to end the political impasse that brought down the Third Republic through the military coup in 1996. Amnesties for those involved in both the 1996 and 1999 coups were part of the constitutional draft.
In the October–November 1999 elections, Mamadou Tandja was elected to a five-year term. His party, the MNSD, took 38 of 83 parliamentary seats. On 5 January 2000, Tandja'a government was installed. Its 23-members are mainly MNSD-CDS faithful, including Prime Minister Hama Amadou. Two small parties supporting Tandja on the second round received minor portfolios. Four ministers from Wanké's government retained their posts.
The National Assembly, elected for a five-year term, had 75 members elected in multi-seat constituencies, and 8 members elected in single-seat national minority constituencies. Next elections were due November 2004.