After World War II, most Polish political parties active during the interwar period were forced to remain in exile and continue their activity. Among these parties was the Polish Socialist Party (PPS), which was established in 1892. Many well-known activists of the party such as Zygmunt Zaremba, Adam Ciolkosz, Adam Pragier and Tomasz Arciszewski, the last prime minister of the Polish government in exile recognized by the Western allies, settled in England. The Polish Socialist Party was part of the international social democracy, belonging to the Socialist International, set up in 1951 in Frankfurt, and Adam Ciolkosz was a member of the team which prepared the programmatic declaration on the International 'Aims and Tasks of 'Democratic Socialism'. Polish socialists in exile considered themselves representatives of the Polish society that could not freely express its views under Communist rule. The socialists were convinced that when Poland regained full independence, people in free elections would opt for their program. They called it the 'socialist alternative' to 'communist dictatorship.' In general, the PPS program coincided with the objectives of 'democratic socialism', although it must be admitted that PPS - in contrast to most social democratic parties of the West - never rejected the Marxist analysis of social phenomena. PPS worked very closely with the parties from socialist countries operating in exile and behind the Iron Curtain. The parties were grouped in the 'Socialist Union of Central-Eastern Europe'.