[2] The party promoted "social union" rather than opposition between urban and rural interests, advocating for the renovation of socio-economic structures based on agriculture.
During the 1945 elections, the party allied itself with the political right, opposing ongoing transformations but achieving limited national presence.
Following the elections, eleven MPs, including five affiliates, formed the Peasant Group, aligned with the Democratic and Socialist Union of the Resistance.
In 1957, party leader Paul Antier was expelled from the CNIP after forming an alliance with Pierre Poujade's Union et Fraternité Française.
Antier retained control of the PPUS, while members loyal to the CNIP formed the Peasant and Social Union Movement (MUPS).