Throughout the 1920s Canadian politicians, immigration officials, eugenicists and political commentators talked about the need to ‘Canadianize’ all migrants who arrived in the dominion, including those from the mother country. This did not mean that Ottawa was out to ‘de-Britannicize’ those arriving from the United Kingdom. British migrants were given preferred status because their common heritage and shared cultural values mirrored those of most Anglo-Canadians. In other words, ‘Britishness’ made up the bedrock of Anglo-Canadian ‘national’ identity prior to the Second World War. Nonetheless, tensions existed between the competing notions of what it was to be ‘British’, ‘Canadian’ or what John Darwin has posited, the formation of a ‘Britannic’ identity. Using the formulation and implementation of assisted migration and empire settlement between 1919 and 1930 as a backcloth, this paper chronicles the long forgotten controversy surrounding the competing national and imperial interests that exacerbated relations between London and Ottawa after the Great War.