The Polish United Workers’ Party (Polska Zjednoczona Partia Robotnicza, or PZPR) was established in December 1948 through a forced merger of the Polish Workers’ Party (PPR) and the Polish Socialist Party (PPS). It remained the ruling Marxist-Leninist party in Soviet-occupied Poland until the Round Table Agreements and the elections of 1989. At its eleventh and final congress held on 27-30 January 1990, the PUWP was officially disbanded and the party banner was removed from the hall.
Former PUWP activists, including former Prime Minister Mieczyslaw Rakowski, Leszek Miller, and Aleksander Kwasniewski, immediately formed a successor party, the Social Democracy of the Polish Republic (SdRP). The new organization assumed control …
Styrna, Pawel. "Reform and renaming of Communist Party in Poland". The Literary Encyclopedia. First published 26 June 2009
[http://www.litencyc.com/php/stopics.php?rec=true&UID=4099, accessed 04 December 2016.]