Ritchie, who, guided by the free-trade ideas of the leading economists of the time, such as Sir William Ashley, was vigorously opposed to any scheme of Imperial Preference. This ultimately resulted in a damaging rift within Balfour's Conservative-Unionist coalition government, contributing to its defeat in the 1906 elections. During the 1920s, Imperial Preference became popular once more, mostly through the good will of Lord Beaverbrook and his Daily Express, once Lloyd George was ejected from office. Unfortunately for Beaverbrook, Bonar Law preferred Lord Derby and his fear of opposition to a policy of extra-mural Food Tax, and Beaverbrook was unable to adapt his scheme, perhaps because of the economics: Law died in office before his first year in power was complete, and was succeeded by Stanley Baldwin, who was a tepid supporter of the scheme. He called the 1923 elections specifically to introduce protectionist policies and lost, leading to the first minority Labour government. Baldwin's Conservatives came back to power after the 1924 elections without a protectionist policy. His Colonial and Dominions Secretary, Leo Amery, was one of its strongest supporters and in 1926 established the Empire Marketing Board to encourage Britons to 'buy Empire'. But Winston Churchill, Chancellor of the Exchequer of the Baldwin government, a former Liberal and always a no-holds-barred free trader, was an opponent. Public opposition to protectionism contributed to the Conservative loss of power again in the 1929 elections and the creation of the second Labour government. The 1931 elections supported a National Government nominally led by former Labour prime minister Ramsay MacDonald but with an overwhelming majority of MPs being Conservatives under Baldwin; these largely supported Imperial Preference as a response to the Great Depression. In 1932, representatives of Britain, the Dominions, and the Colonies held the Commonwealth Conference on Economic Consultation and Co-operation in Ottawa, Ontario, Canada. They agreed to implement policies of Imperial Preference for five years. This new policy was based on the principle of "home producers first, empire producers second, and foreign producers last" In 1935, the Canadian Prime Minister, R. B. Bennett, a Conservative endorsed Imperial Preference. After World War II and the signing of the General Agreement on Tariffs and Trade in 1947, the extension of preferential tariffs was prohibited and the margins reduced. Inflation, combined with the general liberalisation of trade around the world, ended the formal system of imperial preference. 21st Century Brexit has sparked increased