Tarka then emerged as president of the United Middle Belt Congress (UMBC), the party soon formed an alliance with the Action Group, the dominant party in the Western Region. Action Group wanted support for the merger of Ilorin and Kabba with the Western Region and UMBC wanted the creation of a Middle Belt State. Tarka was a nominated member to the Nigerian Constitutional Conference of 1957 and was also the representative of the Middle Belt zone to the Willinks Commission of 1958. In 1958, he was appointed as a shadow minister of commerce.