This article examines French Catholics’ recruitment, organisation, and policing of Muslim participants in the 2012-2013 anti-same-sex-marriage protests La Manif Pour Tous. It argues that French Catholics are alert to forms of public participation which suggest religious ‘intransigence’ (strict religious observance) and can be said to transgress the secular character of the public sphere. Instead, they craft a public presence which can be interpreted as secular, or ‘liberally’ religious-and-secular, without passing the implicit threshold of intransigence. But French Catholics’ efforts to police Muslims’ and their own public visibility reveals the subjectivity and impermanence of the thresholds which are held as proof of religious intransigence. This article contributes ethnographic evidence to the historical and sociological investigation of ‘liberal’ versus ‘intransigent’ forms of French Catholicism, and advances the anthropological study of the inequalities and privileges of Muslim and Catholic representation in secular French politics.