After independence the attitudes of the major parties toward the formation of new states that could accommodate minority aspirations varied widely. The NCNC espoused self-determination for ethnic minorities but only in accordance with its advocacy of a unitary state. The Action Group also supported such movements, including the restoration of the northern Yoruba area (Ilorin) to the Western Region, but as part of a multistate, federal Nigeria. The NPC steadfastly opposed separatism in the Northern Region and attempted with some success to win over disaffected minorities in the middle belt.

Proposals were introduced for the creation of three states as a means of restructuring the regions along ethnic lines. The most extensive revision sought the separation of the middle belt from the Northern Region, a move the United Middle Belt Congress promoted. Serious riots in Tivland in 1960 and 1964 were related to this agitation. Another plan was put forward by the Edo and western Igbo to create the Midwestern Region by separating the whole tract adjacent to the Niger River from the Yoruba-dominated Western Region. At the same time, Ijaw and Efik-Ibibio ethnic groups proposed that the coast between the Niger Delta and Calabar become a new region in order to end Igbo dominance in that area. At this time, however, only the Midwestern Region achieved formal approval, despite opposition of the Action Group. The creation of the region was confirmed by plebiscite in 1963.

The creation of the Midwestern Region reopened the question of the internal restructuring of Nigeria. One motive for a more drastic restructuring was the desire to break up the Northern Region. That region, having more than half the country's population, controlled a majority of the seats in the House of Representatives. There was also the fear that the Igbo-dominated NCNC would gain control of the Midwestern legislature and thereby become even more powerful. A new political coalition, the Midwest Democratic Front (MDF), was formed by leaders of the Action Group and the United People's Party to contest the Midwestern Region election with the NCNC. During the campaign, the conservative United People's Party accepted support from the NPC, a fact that NCNC candidates stressed in their call to keep northern influence out of the region. Many Action Group workers withdrew support from the MDF in protest, and some allied themselves with the NCNC. In the 1964 elections, the NCNC won by a landslide.

Data as of June 1991