The Cameroon National Union (Union Nationale Camerounaise—UNC) was Cameroon's sole legal political party until 1990. It was formed in 1966 through a merger of the Cameroon Union (Union Camerounaise) and the Kamerun National Democratic Party, the major political organizations, respectively, of the eastern and western regions, and four smaller parties. The UNC sponsors labor, youth, and women's organizations and provided the only list of candidates for the 1973, 1978, and 1983 legislative elections.
Ahmadou Ahidjo became the first head of the UNC in 1966 and continued in that capacity after his resignation as the nation's president in 1982. Following President Biya's assumption of emergency powers in August 1983, Ahidjo, then in France, resigned as party leader. Biya was subsequently elected party chief at a special party congress in September. In 1985, the UNC was renamed the Cameroon People's Democratic Movement (CPDM or Rassemblement Démocratique du Peuple Camerounaise—RDPC).
Opposition parties were legalized in 1990. In the elections to the National Assembly on 1 March 1992, the RDPC/CPDM won 88 of the 180 seats; the National Union for Democracy and Progress (UNDP), 68 seats; the Union of Cameroonian Populations (UPC), 18 seats; and the Movement for the Defense of the Republic (MDR), 6 seats. The RDPC/CPDM and the MDR formed a coalition.
In the presidential election of 11 October 1992, the voting was split— RDPC/CPDM 40%; Social Democratic Front (SDF), 36%; and UNDP 18%. The SDF accused Biya of stealing the election, but Biya was reelected to his post as head of the RDCP/CPDM in October 1995.
In the May 1997 National Assembly elections, the RDPC/CPDM took 109 seats, the SDF 43, the UNDP 13, the UDC 5, others 3, and cancelled constituencies 7. The opposition, backed by international observers, declared the legislative elections highly flawed, and based on their perception of misconduct, the main opposition parties boycotted the presidential elections of October later that year.
The SDF and its allies in the Union for Change remain critical of Biya but are also critical of France, which they call an "accomplice of those in power." However, in 2000 the alliance reportedly was falling apart as the SDF sought to distance itself from the SCNC. The SCNC apparently was accusing the SDF of delaying independence for the northwest and southwest English-speaking provinces by refusing to force its English-speaking members of parliament to resign from the Francophonedominated National Assembly. Moreover, some members of the opposition wanted their party leaders to join Biya's coalition government so they could share the spoils of office.
By 2000, Biya had shored up his government by forming a coalition with the northern-based UNDP, which had 13 Assembly seats, and with the UPC, which had one seat. Together, the ruling coalition gave Biya a four-fifth's majority in the Assembly. The coalition government enjoyed support from seven of Cameroon's 10 provinces, and thus secured former President Ahidjo's north-south alliance, which he had created in 1958.
In the June and September 2002 National Assembly elections, the RDPC/CPDM took 149 seats, the SDF 22, the UDC 5, the UPC 3, and the UNDP 1. Voting irregularities in 9 constituencies (17 seats) in the June elections led to the subsequent by-elections in September for those seats. Nineteen of the SDF's seats came from the English-speaking northwest province. The biggest loser in the election was the UNDP: it had won 68 seats in 1992 and 13 seats in 1997. Observers attributed the party's poor showing to its participation in the RDPC/CPDM-led government.