The Second World War marked the beginning of a new period in the colonial policy of Great Britain. In 1945, the House of Commons approved an Act of Colonial Development and Welfare, primarily aimed a financial support to the underdeveloped African colonies. Under this Act, the emphasis was placed on the implementation of large-scale socio-economic projects designed to promote the developments of industry and agriculture, and to improve the living standards of the colonial population. The Attlee government tried to reconcile these tasks with the plans to strengthen the British economy and the overall unity within the British Empire facing the decolonization process. Among major socio-economic projects in the general policy of colonial development in the second half of the 1940s was the groundnuts cultivation in Tanganyika. Basing on the British documents of the Colonial Office, Ministry of Food and Cabinet, the author analyses the progress of the “Groundnuts Scheme” and the reasons for its failure. Particular attention is paid to the governmental discussions that accompanied the developments of this and similar projects, and attempts by the Labour Party to “rescue” the project. The author concludes that the Attlee government made a series of miscalculations subsequently resulted in a refusal from a partially realized project, even before the project started. The government also erroneously valued the possibilities of colonies’ economy.