Parliamentary debate is an institutional activity with its own practical ends, corresponding to a logic that is specific to some extent and framed by particular procedures which are discursively and procedurally limited. This article analyses an Egyptian parliamentary debate concerning a scandal on the Islamic headscarf. The debate sequentially transformed an affair started in the media, into a parliamentary object marked by the game of political representation and oriented towards both the inside and the outside of parliament. The analysis of this debate enables the authors to show in detail the motivations behind the situated political action of the members of a specific assembly, on a question of public morals.