Popular Unity (Italian: Unità Popolare, UP) was a short-lived social-democratic and social-liberal and political party in Italy.It was formed in April 1953 by disgruntled members of the Italian Democratic Socialist Party (PSDI) and the Italian Republican Party (PRI), who did not agree with the new electoral law approved by the Parliament with the support of their parties. Its leaders were Piero Calamandrei, a Democratic Socialist, and Ferruccio Parri, a Republican and former Prime Minister.