In the period just before and after the Second World War, the party became a champion of 'progressive social policy'. As Prime Minister for most of the time between 1921 and 1948, King introduced several measures that led to the creation of Canada's social safety net. Bowing to popular pressure, he introduced the mother's allowance, a monthly payment to all mothers with young children. He also reluctantly introduced old age pensions when J. S. Woodsworth required it in exchange for his Co-operative Commonwealth Federation party's support of King's minority government.