 After the proclamation of the Third Republic, and the subsequent legalization of opposition parties in 1990, Nguza started his own party, the "Union of Federalists and Independent Republicans".He later replaced Étienne Tshisekedi as Prime Minister, after Tshisekedi tried to block Mobutu from accessing cash at the central bank.Nguza was regarded by other members of the Sacred Union (of which his party was a member) as a "traitor" because of this, and he subsequently left the Sacred Union.