المختار ولد داداه
The UPM was established in February 1948, in order to form a more conservative and regionally-based opposition to the Mauritanian Agreement party. The first election contested by the party was the 1951 French National Assembly elections, in which its candidate Sidi el-Mokhtar N'Diaye defeated the incumbent MP Horma Ould Babana. The following year Moktar Ould Daddah became party leader. The Territorial Assembly elections that year saw the UPM won 22 of the 24 seats.