High Quality Content by WIKIPEDIA articles! Social Democracy of the Republic of Poland (Polish: Socjaldemokracja Rzeczypospolitej Polskiej, SdRP) was a social-democratic political party in Poland created in 1990, shortly after the Revolutions of 1989. The party was one of two successor parties to the Polish United Workers Party, the other being the Social Democratic Union. SdRP was the leading party of the Democratic Left Alliance (SLD) coalition grouping, formed in 1991. In 1999, SdRP was absorbed into the SLD, which transformed into a unified political party.