After 1945 , he became involved with the Belgian socialist trades union , the General Federation of Belgian Labour ( FGTB ) .
After 1945 , he refused to adapt his populist rhetoric to fit within the mainstream Belgian Socialist Party ( PSB ) .
After 1945 , he became involved with the Belgian socialist trades union , the General Federation of Belgian Labour ( FGTB ) but refused to adapt his populist rhetoric to fit within the mainstream Belgian Socialist Party ( PSB ) .