He resigned both positions after the report of the inquiry into the affairs of the district council. He was replaced by J.M. Johnson as Minister of Social Services. In 1956, Adelabu again ran for a seat in the regional assembly but this time as leader of NCNC in the Western region. Hoping to lead the party to victory, he had ordered clothes with the inscription Adelabu, Premier of the Western Region. However, the party lost majority seats to Action Group. Adelabu then became the leader of opposition in the Western House of Assembly. After the loss, Adelabu sought to carve out a Yoruba Central State from the Western Region. The new state was to be composed of NCNC strongholds of Oyo, Ibadan and Ondo provinces. However, the proposal was rejected in 1958 based on the proposed division on largely on party lines. In 1958, Adelabu opposed the leadership of Azikiwe because of its support for a tripartite national government consisting of AG, NCNC and NPC. Adelabu did not like the inclusion of AG describing it has an unholy alliance.