During the communal election organised before independence, he was elected as a municipal councilor and member of the Élisabethville council. In 1960, he was elected as a national MP for the Tanganyika constituency. He was appointed Secretary of State for National Defense as a CONAKAT party member in the
Lumumba Government. He was a Secretary of State, since the portfolio of National Defense was added to the Prime Minister's. Eleven days after Congo's independence, Moïse Tshombe declared the independence of the
State of Katanga. At the start of the secession, four delegations were sent out to explain the government's point of view. The second delegation, led by Minister of Foreign Affairs
Évariste Kimba, included Nyembo,
Gabriel Kitenge, Cyprien Kayumba Mfumu wa Bwana, Léonard Kanyangala, and an ordinance officer, and left for Europe at the start of August. After the secession ended, he was appointed Minister of National Economy in the
Cyrille Adoula government of the reunified Congo. In 1965, he became a national MP for Tanganyika. Nyembo was also active as a manager, as a President of the
Compagnie du chemin de fer du Congo supérieur aux Grands Lacs africains in 1964 and President of in 1973. During the national elections for the
Bureau politique (political office) in 1970, he was elected a political commissioner for the
Shaba region. He served for the
Bureau politique of the sole party
Popular Movement of the Revolution (MPR) from 22 November 1977 to 18 February 1981. He was a member of the Central Committee of MPR since the announcement of its composition on 2 September 1980. He was President of the Financial and Economic Commission from the beginning until March 1984. His mandate at the Central Committee was renewed on 28 January 1985. == Honours ==