The political groupings that emerged in Sudan's struggle for independence focused on personalities or specific interest groups rather than ideology or party machinery. The most powerful force before 1958 was the Ansar sect and the Ansar-sponsored Ummah Party. Other parties were closely affiliated with the Khatmiyah sect, led by Sayyid 'Ali al-Mirghani; the leftistdominated labor unions; the Graduates Congress, an organization of college graduates; and leaders of the black tribes of the south. For the first three years of the country's independence, these parties were strongly divided on such issues as union with Egypt (opposed by the Ummah Party); alignment with the West in economic and foreign affairs (opposed by the Khatmiyah, the labor unions, and the Graduates); Communism (courted by elements in most parties and labor unions); political secularization (sought by leaders not aligned with the religious sects); federalism (demanded by southern spokesmen); and fear of the royal aspirations of the Mahdi family. These divisions helped bring about the downfall of several coalition cabinets and finally weakened the parliamentary system to the point where the army could successfully carry out a coup without encountering resistance. Political activity was banned in 1958 and was not resumed until the overthrow of the Abboud government in October 1964.
In 1966, the Ummah Party split into two groups, one conservative, the other progressive. The following year, the Democratic Unionist Party (DUP) was formed from the amalgamation of the National Unionist Party and the People's Democratic Party. In the May 1968 elections, the DUP won 101 of 218 parliamentary seats, while no other party captured more than 36.
After the 1969 military takeover, existing political parties were banned, and a special attempt was made, beginning in 1971, to suppress the powerful Communist Party. The 1973 constitution provided for a one-party state, with the Sudanese Socialist Union (SSU), established by Nimeiri in 1971, as the sole legal political organization. In elections for the National People's Assembly, only candidates approved by the SSU were allowed to run.
In April 1986, in the first free elections held since 1968, the Ummah Party won 99 of 301 parliamentary seats, the DUP won 63, and the fundamentalist National Islamic Front (NIF) won 51.
The remaining seats went mainly to regional parties, but 37 seats from the south were unfilled because of the civil war and the boycott of the elections by the Sudanese People's Liberation Front. The Ummah Party, the DUP, and four southern parties formed a coalition government, with the NIF in opposition. In August 1987, the coalition fell apart when the DUP broke away from the Ummah Party after an election in which it lost one of its two seats on the Supreme Council to an Ummah candidate, reportedly because the DUP candidate had been a close aide of Nimeiri. Prime Minister Sadiq al-Mahdi, aligned with the Ummah Party, retained his position until his overthrow in June, 1989.
In the elections for the National Assembly, held (except in the south) from 21 April to 8 May 1965, the Ummah again emerged as the most important party, gaining 76 of the 173 contested seats. The National Unionist Party, a right-wing party favoring close relations with Egypt, won 53 seats and formed a coalition government with the Ummah Party. During the mid-1960s, two regional parties—the Southern Front, formed in 1964 by Southerners living in the north, and the Sudan African National Union (SANU), formed in 1966 by Sudanese exiles in Uganda— advocated self-determination and independence for the south.
The RCC banned all parties in 1989 except for the NIF, whose members and supporters held most key positions. After the dissolution of the RCC in October 1993, the NIF further tightened its grip on the state. The RCC's executive and legislative powers were transferred to the president and the Transitional National Assembly (TNA), Sudan's appointed legislative body, which was replaced by the National Assembly elected in March 1996.
The main opposition to the central government became the Sudan's People's Liberation Army (SPLA) which joined forces in 1997 with a new alliance of northern rebels known as the National Democratic Alliance. This opposition has been sponsored by Ethiopia and Eritrea, and encouraged by the United States, which holds the government of Sudan responsible for sponsoring international terrorism, and for committing atrocities against its Christian population in the south.
A new constitution adopted in 1998 and revised in 2000 recognized political parties other than the NIF for the first time since 1989. However, parties had to accept the constitution and refrain from advocating or using violence against the regime. Approved parties include the ruling National Congress Party (NCP) led by Ibrahim Ahmed Umar, Popular National Congress (PNC) led by Hassan al-Turabi, and over 20 minor progovernment parties. As of early 2000, the leaders of two other major parties, the Ummah Party and the Democratic Unionist Party (DUP), who had cooperated with the SPLA rebels to form the National Democratic Alliance, were still in exile. In the fall of 1998, the National Islamic Front (NIF) changed its name to the National Congress party.
In elections held in December 2000, al-Bashir was reelected president with 86.5%, followed by Ja'afar Muhammed Numayri with 9.6%. Three other candidates received less than a combined 4% of the vote. In the boycotted parliamentary elections of 13-22 December 2000 the NCP took 355 of 400 seats.