This article analyses the parliamentary phenomenon that historians have referred to as the ‘halo effect’. A model adopted by Nancy Astor, the ‘halo effect’ describes candidates fighting parliamentary seats that had previously been contested by their spouse and accounted for almost a third of the women elected to parliament between the wars. Instead of dismissing its presence as a lack of political progress for women post-suffrage, this article suggests that the ‘halo effect’ was part of the early attempts of political parties to accommodate gender in public life. It indicates the continued relevance of the family as a political organising unit within the era of mass democracy. Rather than understanding seat inheritance between spouses as simply nepotism, this article demonstrates that, for women, their status as wives provided excellent political training and a committed political partner to help them in their careers. Beyond ‘male equivalence’, their relationships helped them to present an identity that allayed some of the tensions surrounding women in public political life and partly accounts for the great success of the ‘halo effect’ in bringing women into parliament in this era.