Independent Radicals

The Independent Radicals () were a right-of-centre French political current during the French Third Republic. It was slightly to the right of the more famous Radical-Socialist Party, and shared many doctrinal features in common. The prominent political scientist André Siegfried described them as "Social [that is, economic] conservatives who did not want to break with the Left, and who therefore voted with the Right on [economic] interests, and with the Left on political issues".
Parliamentary origins and influence.
Originally in the 1900s French political parties were extraparliamentary organisations focussed entirely on campaigning, separate from the associated parliamentary group. Two 'Radical' parliamentary groups existed, sharing a certain overlap in ideology: the Radical-Socialist group and the Radical Left group. In 1914 the Radical-Socialist Party ordered all candidates elected on its ticket to sit exclusively in the Radical-Socialist group, creating a clearer boundary between the two parties: the Radical Left group was now the parliamentary party of 'Independent' Radicals who quit the Radical-Socialist Party as well as those who refused to join it, normally out of disagreement with the Radical-Socialists' preference for allying with the Socialist Party.
From 1914 to 1940, Radical Republicans in parliament were therefore mostly split into two distinct groups, on the one hand the Radical-Socialist Party and on the other the Independent Radicals some of whom sat unaffiliated but most sitting in the Radical Left group. This largely came down less to ideology and rather their preference in coalition partner: the Socialist Party to their left or the secular conservative-liberals of the centre-right Democratic Alliance. This made the Radical Left a pivotal party, and regardless of whether the government was centre-left or centre-right there was usually one or more Independent Radical in cabinet. Several of France's most powerful political figures were Independent Radicals, including Prime Minister Georges Clemenceau and President Gaston Doumergue. 
Developments during the interwar period.
At various moments during the interwar the Radical-Socialist Party was subject to small schisms over its attitude to the government of the day. Whenever the more conservative Radical-Socialists quit their caucus, they would either join the Radical Left group directly, or form a small splinter Radical group that eventually merged into the Radical Left. In 1938 an Independent Radical Party was formed from the merger of two groups that had at different points split off from the Radical-Socialist Party in protest at its choice of allies: Henry Franklin-Bouillon's anti-socialist Social and Unionist Radicals (formed in 1927), and André Grisoni's anti-communist 'French Radical Party' (formed in 1936).
The tendency was described by André Siegfried (Tableau des Partis en France) for the case of Franklin-Bouillon's dissidents: "a group largely of former Radical-Socialists who from a sense of National Unity, preferred to side with Poincaré [the liberal centre-right] over the Cartel [Socialist Party], and who ended up turning vaguely into nationalists. Radicalism has always contained this kind of temperament, but has always ended up expelling them. Are they really a party of the Centre[-right]? In any case they have taken refuge there, without fully sharing the mindset, and in any case the pure Radical[-Socialist]s would not forgive their dissidency and welcome them back."
It is worth noting, however, that the Radical-Socialists did welcome some of them back, and on the margins of the two parties there was much overlap and back-and-forth. The most noteworthy rogue Radical-Socialist to be reinstated was Albert Sarraut, leader of the party's right-wing, who during his expulsion from the party between 1924-5 continued to sit as an independent Radical. Others include the Breton deputy Pierre Michel, who in 1932 initially chose to sit among the Radical Left group before, a year later, moving permanently to sit with the Radical-Socialist group.
Over time the boundaries between the Independent Radicals and the Left Republicans group (caucus of the Democratic Alliance) grew less clear. In 1936 an attempt was made by the liberal former-premier Pierre-Étienne Flandin to merge the two groups under the label Alliance of Left Republicans and Independent Radicals (ARGRI). It ultimately failed: while some Independent Radicals joined, others refused and continued the old caucus under the name "Independent Radical and Democratic Left" group. While today the distinction between conservative Radicals and conservative Liberals appears arcane (these two tendencies had already merged, or would later merge, in most European countries), at the time there was a genuine difference in temperament.
In 1930, the Independent Radical Raoul Péret became Minister of Justice in André Tardieu's cabinet. He was incidentally the cause of his fall because of his personal links with the banker Albert Oustric.
In the Senate, the Independent Radicals sat in the Democratic and Radical Union ("Union démocratique et radicale") parliamentary group.
After the Liberation of France, several deputies, including the mayor of Nice, Jean Médecin, formed an Independent Radical Party (PRI), which was a founding member of the Rally of Left Republicans umbrella party.