Retiring from politics, Pierlot returned to practicing Law in Brussels. In 1946, a book entitled the "Livre Blanc" (White Book) was published at the request of Leopold, defending the King and attacking the exile government's record. Responding to the criticism, Pierlot published a widely distributed series of articles in the newspaper "Le Soir". He remained a controversial figure. King Baudouin, replacing his father as King in 1950, also refused to receive Pierlot at the palace. After 1947, he refused to return to politics or to respond publicly to criticism from his political enemies.