At independence in 1961, Tanganyika (Tanzania Mainland) had a multiparty political system. The Tanganyika African National Union (TANU), established in 1954, was the overwhelmingly dominant political party in preindependence Tanganyika. Other political parties of this era included the United Tanganyika Party, the African National Congress, and the All Muslim National Unity of Tanganyika. In Zanzibar, there were three important political parties prior to independence. These were the ZNP (Zanzibar Nationalist Party, ASP (Afro-Shirazi Party), and ZPPP (Zanzibar and Pemba Peoples's Party). On February 5, 1977, ASP the ruling party of Zanzibar and TANU merged into the Chama Cha Mapinduzi (CCM) or Revolutionary Party. It became the sole legal political party in Tanzania. All candidates had to be approved by the CCM and were permitted to campaign only on the CCM platform. Elections within the single party framework were competitive, however. In the balloting on 13 and 27 October 1985, 328 candidates competed for 169 elective seats in the National Assembly. In 1987, former president Julius K. Nyerere was reelected chairman of the CCM. He stepped down in 1990, to be succeeded by Ali Hassam Mwinyi.
The CCM officially favors nonracism and African socialism. The basic aims, laid down in Nyerere's Arusha Declaration of 1967, are social equality, self-reliance, economic cooperation with other African states, and "ujamaa" (familyhood), the development of forms of economic activity, particularly in rural areas, based on collective efforts. However, since the late 1980s, CCM has slowly transformed itself into a pro-market, pro-business party. The party is divided into locally organized branches, which are grouped into districts, which in turn are grouped into regions. The 172-member National Executive Committee is the principal policymaking and directing body of the CCM. A central committee of 18 members is elected at periodic party congresses.
Although Tanzania amended its constitution in 1992 to become a multiparty state, the CCM still controls government. Other parties have tried to organize, and have complained of harassment by government and CCM activists. Before taking part in elections, the new parties undergo a six-month probation during which they can recruit and organize. Some 20 opposition groups had registered in the first four months of their legality. However, parties representing regional, racial, ethnic, or religious groups are explicitly prohibited.
Multi-party elections were held in Zanzibar on 25 October 1995 and union-wide on 29 October 1995. International observers and opposition parties accused the CCM of voter fraud and intimidation of opposition candidates in Zanzibar. While CUF claimed victory, on 26 October, the election commission declared CCM presidential candidate Salmin Amour the winner by 1,565 votes over the CUF's Seif Shariff Hamad. The CCM also won 26 of the 50 seats in the House of Representatives. Citing fraud in the election, the CUF boycotted the House and refused to recognize the Amour government. CCM-CUF tension in Zanzibar increased dramatically after the government arrested eighteen CUF members and charged them with treason, an offence punishable by death. Four of those charged with treason were CUF members of the Zanzibar House of Representatives. The Commonwealth Secretary General, Chief Emeka Anyaoku tried to reconcile the two parties. An agreement was reached between the two parties in 1999 but tensions on the island remained high as CUF charged CCM with not living up to the agreement. As the 2000 elections approached, the treason suspects were still behind bars and clamoring to run for office from prison.
The Union election held on 29 October 1995 was so disorganized that it was cancelled in Dar es Salaam and held again on 19 November. In the presidential election, CCM candidate Benjamin Mkapa won with 61.8% of the vote. Former Deputy Prime Minister Augustino Mrema of the National Convention for Constitutional Reform received 27.7%; Ibrahim Lipumba of the Civic United Front won 6.4%, and John Cheyo of the United Democratic Party captured 3.97%. Parliamentary election results saw the CCM win 59.2% of the vote and 186 seats; NCCR, 21.83% and 16 seats; CUF, 5% and 24 seats; Chadema, 6.2% and 3 seats, and UDP, 3.3% and 3 seats.
As of the October 2000 elections there were 12 permanently registered opposition parties: Civic United Front/Chama Cha Wananchi (CUF), the National Convention for Constitutional Reform (NCCR-Mageuzi), the Union for Multiparty Democracy (UMD), Chama cha Demokrasia na Maendeleo (CHADEMA), the National League for Democracy (NLD), the Tanzania Peoples Party (TPP), the Tanzania Democratic Alliance (TADEA), the National Redemption Alliance (NRA), the Popular National Party (PONA), the United Peoples Democratic Party (UPDP), the United Democratic Party (UDP), and the Tanzania Labor Party (TLP).
In the presidential elections on 29 October 2000, CCM candidate Benjamin William Mkapa was reelected president with 71.7% of the vote, defeating CUF candidate Ibrahim Haruna Lipumba who garnered 16.3%. TLP candidate Augustine Lyatonga Mreme managed to obtain 7.8%, and John Momose Cheyo of the UDP 4.2%. In the National Assembly, the CCM won 244 of 272 seats to 16 for the CUF, 4 for CHADEMA, 3 for TLP, and 2 for UDP. In the Zanzibar House of Representatives the CCM won 34 seats to 16 for CUF. However, on Zanzibar the elections and post-elections period were marred by violent civil unrest. The next elections were scheduled for October 2005.