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. On 14 January 2005, the group was renamed to the Centrist Union – Union for French Democracy group (
groupe Union centriste – Union pour la démocratie française, abbreviated UC–UDF), a denomination which it retained until 29 September 2008, when it became then Centrist Union group (
groupe Union centriste). The group was renamed again in 2011, this time to become the Centrist and Republican Union group (
groupe Union centriste et républicaine) after the arrival of three
radicals of the UMP. In 2012, the
Union of Democrats and Independents (UDI), uniting most of the parties of the centre – the
Radical Party (PR) of
Jean-Louis Borloo, the
New Centre (NC) of
Hervé Morin,
Centrist Alliance (AC) of
Jean Arthuis,
Modern Left (LGM) of
Jean-Marie Bockel, and
Democratic European Force (FED) of
Jean-Christophe Lagarde – was founded, notably without the participation of the
Democratic Movement (MoDem) of
François Bayrou, whose members are part of the senatorial group. and on 23 October the group was officially renamed to the Union of Democrats and Independents – UC group (
groupe Union des démocrates et indépendants – UC), and briefly took upon its unabbreviated form in 2017, registered as the Union of Democrats and Independents – Centrist Union group (
groupe Union des démocrates et indépendants – Union centriste). After the Centrist Alliance announced its support for
Emmanuel Macron in the
2017 presidential election, it was expelled from the UDI, though its senators remained within the group. On 3 July 2017, the UDI–UC group, chaired by
François Zocchetto, voted in support of a motion placing the 42 members of the group within the presidential majority of Macron following his election, with 4 senators abstaining; this was in contrast to the decision of the deputies in the
National Assembly part of
The Constructives: Republicans, UDI, and Independents group, of which two-thirds abstained during the vote of confidence in the government. With a consensus among its senators to support the reform efforts of Macron, the group returned to its old denomination of the Centrist Union group (
groupe Union centriste). As in the lower chamber, MoDem senators within the group decided not to join the
La République En Marche group in the Senate, preferring to support the government within the existing centrist group. On 26 September,
Hervé Marseille was elected the new president of the group following the
renewal two days earlier.