The Centrist Union (, abbreviated UC) is a centrist parliamentary group in the Senate uniting members of the Union of Democrats and Independents (UDI) and Democratic Movement (MoDem), as well as the Centrist Alliance (AC), a former component of the UDI. The group was historically associated with the Popular Republican Movement (MRP) and later the Democratic Centre (CD), Centre of Social Democrats (CDS), and Union for French Democracy (UDF). Most recently, from 2012 to 2017, it was known as the Union of Democrats and Independents – UC group (, abbreviated UDI–UC).
History
In the first election of the Council of the Republic of the Fourth Republic, the Popular Republican Movement (MRP) group (groupe du Mouvement républicain populaire) obtained 76 seats, a quarter of the upper chamber, following senatorial elections on 8 December 1946. During the debate on the existence of the upper chamber, the MRP advocated for a bicameral system in which both the roles and modes of election of the two houses were clearly distinguished from each other, calling for the replacement of the system of indirect universal suffrage to select electors with greater representation of local collectivities. This proposal eventually prevailed despite the reluctance of certain members of the MRP, cognizant of the fact that such a system would favor it significantly less. Indeed, with a lack of representation at the local level as a result of the 1947 municipal elections in which the newly-founded Rally of the French People (RPF) of Charles de Gaulle secured a massive victory (the RPF having deprived the MRP of its flag as the party of the resistance), the MRP was reduced to just 22 seats following the senatorial elections of 7 November 1948. and never regained its former strength through the duration of the republic, with 24 seats following senatorial elections on 18 May 1952, 21 seats following senatorial elections on 19 June 1955, and 23 seats following senatorial elections on 8 June 1958.
In the Fifth Republic, the group was reincarnated as the Popular Republicans group (groupe des Républicains populaires), presided over by Alain Poher, with the Democratic Centre formation (formation du Centre démocratique) administratively attached to it, with Yvon Coudé du Foresto serving as its secretary. In January 1959, the MRP received a proposal from the Rally of Democratic Forces (Rassemblement des forces démocratiques, abbreviated RFD) envisaging the "establishment in France of a very large rally inspired by an ideal of political, economic, and social democracy", with the RFD consisting of a number of members of Catholic youth movements, some part of the MRP, including Rémy Montagne, Michel Debatisse, Bernard Lambert, and Nestor Rombeaut. Negotiations began immediately and significant progress was made until the issue of the denomination of the movement was raised, with its general secretary Maurice-André Simmonet objecting, noting that the name was popular with voters. In the 1959 renewal, the group secured 34 seats, an achievement aided by the increased strength of the MRP within metropolitan France, especially at the level of municipal and regional councils in rural areas; prior to that point, the strongholds of the MRP had largely been located in overseas France; with the MRP overwhelmed by the success of the RPF in the 1958 legislative elections, six former deputies, including four former ministers, found refuge in the Senate. The ranks of the group were filled with relatively young senators; as a result, it demonstrated greater dynamism, but also greater politicization, in its work.