Hungarian Socialist Workers' Party

In the first days of the October 1956 revolution the ruling Hungarian Working People's Party collapsed rapidly. On 30 October communist leaders decided to dissolve it and found a new party, named the Hungarian Socialist Workers' Party on the proposal of Zoltán Szántó, who had been a politician of the communist cover party of the same name in 1925–1927. A seven-member Provisional Executive Committee including János Kádár, Imre Nagy and György Lukács led the party, and Kádár announced its founding in a radio speech on the evening of 1 November.

The party at first supported the revolution but turned against Nagy's government after it denounced the Warsaw Pact. Of Kádár and Ferenc Münnich, who were in Moscow on 2–3 November, the Soviet leadership entrusted the country to Kádár, and on 4 November his ‘Revolutionary Workers' and Peasants' Government’ took power with Soviet support. According to the English source, the government executed 350 people after the revolution.

Under the motto ‘he who is not against us is with us’ Kádár pursued so-called goulash communism, giving Hungarians more freedom in daily life than their Eastern Bloc neighbours. The New Economic Mechanism introduced some market elements and raised living standards, but the party kept its monopoly of political power and censorship and used the Patriotic People's Front to screen candidates. The Hungarian source says that foreign-currency loans taken after the oil crises of 1973 and 1979 to maintain living standards led to a serious debt trap. In 1986 the party had 883,131 members, 11.1% of the adult population.

At the national party conference of May 1988 Kádár lost power and Károly Grósz became general secretary. On 28 January 1989 Imre Pozsgay announced that a Politburo sub-committee regarded the events of 1956 as a ‘people's uprising’, accelerating change within the party, and radical reformers such as Miklós Németh, Gyula Horn, Rezső Nyers and Pozsgay took over the party machinery. On 26 June a four-man collective presidency chaired by Nyers replaced the Politburo.

At its 14th Congress on 7 October 1989 the party dissolved itself and was refounded as the Hungarian Socialist Party (MSZP), which inherited its assets. Two weeks later the National Assembly approved constitutional amendments removing its Marxist–Leninist character. According to the English source, a minority around Grósz founded the Hungarian Communist Workers' Party on 17 December; the Hungarian source says members who did not join the MSZP continued the congress in mid-December, elected Gyula Thürmer chairman, and renamed their party the Workers' Party in 1992.