This article explores the case of the French cultural institute in London which found itself at the nexus of Gaullist as well as anti-Gaullist networks during the Second World War. By analysing the support that the institute’s director, Denis Saurat, brought to Charles de Gaulle in the early days of Free France, the article contributes to our understanding of the formation of Free French political thought. This study analyses Saurat’s shifting position in the movement, from being Gaullist to becoming an active partisan of anti-Gaullism. The examination of Saurat’s networks and politics helps to re-appraise further trends of anti-Gaullism caused by leftist views not least regarding the lack of democratic principles that characterized Free France in 1940–2. Finally, Saurat’s anti-Gaullism was also prompted by his refusal to put the French cultural institute in London at the service of de Gaulle and support Free French propagandist, cultural and academic ambitions in the world. Overall this article argues for a reassessment of London-based leftist anti-Gaullism understood not just through issues of personalities and democracy but also through the prism of cultural diplomacy and propaganda.