The Left Bloc was primarily formed to counteract the Independent Smallholders' Party, which had won a majority of the vote in the 1945 Hungarian parliamentary election.
The official justification for the Bloc's formation was to defend the country's "progressive achievements" thus far, primarily the land reform enacted in March 1945.
The Bloc's primary demands were the exclusion of "reactionaries" from the government and the nationalization of the banks, mines, and heavy industry, and the three parties organized street demonstrations to force their agenda.
The Communists now held effective power, and thus pressured President Zoltán Tildy to dissolve Parliament and hold early elections.
The Communists also amended the electoral law to exclude some 466,000 voters from the rolls—effectively destroying the Hungarian Freedom Party—while allowing for the registration of many more parties than in 1945 to split the anti-Communist vote.
The Left Bloc was officially dissolved after the 1947 elections, having played a crucial role in Rákosi's "salami tactics" to gradually eliminate the opponents of the Communist Party.