In January 1962, following the Ahidjo's soldiers' dispersal of the Union of the Peoples of Cameroon during its first conference since their rehabilitation, André-Marie Mbida and other opposition leaders, i.e., Marcel Bebey Eyidi (General Secretary of the Labor Party of Cameroon), Charles Okala (General Secretary of the Socialist Party of Cameroon) and Théodore Mayi Matip (deputy and Caucus Chair of The Union of the Peoples of Cameroon), founded a joint committee National United Front () with Mbida as leader. On 23 June 1962, FNU published a manifesto, signed by Mbida, Okala, Eyidi and Matip, in which they affirm their refusal to join the single-party state. The signatories add that a single-party state inevitably leads to dictatorship. Consequently, they were arrested and imprisoned in North Cameroun. This incarceration resulted in a significant deterioration of Mbida's physical appearance: he fell ill and became nearly blind. Following his release from prison in 1965, he was placed under house arrest. In 1966 he obtained permission to seek treatment in France at des Quinze-Vingts Hospital. On returning to Cameroon two years later, he was again placed under house arrest, in Yaoundé, from 3 August 1968 to 30 May 1972.