Proletarian Unity Party (Italy)

The PdUP was founded in the November 1972 by minority factions of two parties: the New PSIUP, led by Vittorio Foa and Silvano Miniati, that gathered the militants of the right wing of the Italian Socialist Party of Proletarian Unity who had not agreed on the decision to join the Italian Communist Party, and Socialist Alternative, led by Giovanni Russo Spena and philosopher Domenico Jervolino, that gathered the militants of the left wing of the Workers' Political Movement who had opposed the merge into the Italian Socialist Party (PSI). Its symbol was the hammer and sickle over the world, inheredited by the PSIUP.

In 1974 these members were joined by the group of Il Manifesto and by the Autonomist Student Movemenet led by Mario Capanna, forming the Proletarian Unity Party for Communism (Italian: Partito di Unità Proletaria per il Comunismo). The founding congress was held on January 29, 1976. Main leaders of the various currents were Miniati, Foa, Capanna (far left-oriented), Rossana Rossanda and Lucio Magri – leaning for collaboration with the Italian Communist Party (PCI) and Italian General Confederation of Labour) – and Luigi Pintor. Magri was elected as the group's first national secretary.

During the 1976 general elections, PdUP ran together with Proletarian Democracy, gaining three seats in the Italian Chamber of Deputies (Magri, Eliseo Milani and Luciana Castellina) elected out of the coalition's 9.

In January 1977, the Manifesto and former-PSIUP affiliates left the party due to the failure in creating an all-left government. On February 20, 1977 the left-wing minority tendency broke away to join Proletarian Democracy in its founding process as organized party.

The Magri's majority absorbed for a while the Avanguardia Operaia movement, which, however, separated in the Congress held at Viareggio the following year. During its third congress (Rome, 1981), the party was joined by the Movimento Lavoratori per il Socialismo, led by Luca Cafiero.

After the elections of 1983 PdUP associated its lists to PCI, to which it had become closer after the PCI secretary Enrico Berlinguer had abandoned the Historic Compromise (a project for a PCI-Christian Democracy alliance).

On November 25, 1984 the Proletarian Unity Party merged into PCI. When, in 1991, Achille Occhetto started the process of transformation of PCI into the Social-Democratic oriented Democratic Party of the Left (PDS), some former PdUP members declared their opposition to the move, and subsequently joined the Communist Refoundation Party. After the latter withdrew from the Centre-left Lamberto Dini government in 1995, many former PdUP members left the party to create the Movement of Unitarian Communists, which later was absorbed into PDS' heir, the Democrats of the Left.