On 8 December 1946 Duchet was elected to the Council of the Republic for Côte d'Or. He helped organize the right-wing Independent Republican group. He was reelected on 7 November 1948, and sat on the Finance and Press committees. In 1949 Duchet,
René Coty and Jean Boivin-Champeaux created the
Centre National des Indépendants (CNI, National Center of Independents), which became the main party of the
French Fourth Republic. Duchet also founded the journal
France Indépendante. During the 1950s Duchet became more conservative. He fought against communism and was in favor of a French Algeria. In the second cabinet of
René Pleven he was Secretary of State for Public works from 11 August 1951 to 4 October 1951, then
Minister of Posts, Telegraphs, and Telephones. He retained the PTT portfolio in the cabinets of
Edgar Faure,
Antoine Pinay and
René Mayer until 28 June 1953. He was Minister of Reconstruction and Housing from 23 February 1955 to 1 February 1956. He was reelected to the Senate on 19 June 1955. During the
French Fifth Republic Duchet was elected to the Senate on 26 April 1959, and was reelected on 23 September 1962. He belonged to the
Groupe des Républicains et Indépendants (Group of Republicans and Independents). The CNI went into decline during the
Algerian War. Duchet was often absent from Beaune. and resigned as mayor in 1965. ==Later career (1965–81)==