The party was taken over by pro-soviet faction in 1946, with the rise of the People's Republic of Poland. As a satellite party it participated in 1947 election, and continued to exist until 1950 when it merged into the Democratic Party (Stronnictwo Demokratyczne), an officially sanctioned party in communist Poland, also described as a "satellite" of the communist Polish United Workers' Party (PZPR).
^Eva Plach The clash of moral nations: cultural politics in Piłsudski's Poland, 1926-1935 (9780821416952): - Footnote Page 205/206 2006 "Party of Work (Partia Pracy) (which had evolved from left-wing peasant party PSL-Liberation) to form the Union of Labour in Town and Village (Zjednoczenie Pracy Wsi i Miast) in June 1928. The Union of Labour in turn formed a core block within the BBWR .."