Following the dissolution of the PSU in 1930, Saragat joined the Italian Socialist Party (Partito Socialista Italiano, PSI).

A reformist, he was a democratic socialist who left the PSI in 1947 out of concern over its then-close alliance with the Italian Communist Party.

He subsequently founded the Socialist Party of Italian Workers (Partito Socialista dei Lavoratori Italiani, PSLI), which in 1952 became the Italian Democratic Socialist Party (Partito Socialista Democratico Italiano; PSDI).

[3] In 1944, Saragat had been a minister without portfolio and ambassador in Paris from 1945 to 1946, before he was appointed president of the Constituent Assembly of Italy that same year upon the establishment of the Italian Republic.

His election demonstrated a rare instance of unity among the Italian left and followed rumours of a possible neo-fascist coup, Piano Solo, during Antonio Segni's presidency.