Based on recently released official documents, the article explores the role played by advanced technology in the Wilson government's efforts to join the Common Market. The analysis focuses on the development of the ultra-centrifuge process – a new technology to produce enriched uranium. The article shows that in restricting collaboration to the Netherlands and West Germany, the British government sought to undermine France's leading role in Europe and to undermine Franco-German relations. It also demonstrates that Britain was determined to establish a European solution to the question of uranium supply even if this led to serious frictions in the Anglo-American special relationship.