The Parti ouvrier-progressiste (in English: Labor-Progressive Party) is the name under which the Parti Communiste du Québec ran candidates from 1944 to 1956, after the banning of the Communist Party of Canada in 1941. Its English counterpart was the Labor-Progressive Party which, federally, elected Fred Rose to the Canadian House of Commons from the Montreal riding of Cartier in 1943.
The POP took its current name (the Parti Communiste du Québec) in 1960.
References
Labor-Progressive Party (Quebec) Wikipedia(Text) CC BY-SA