DescriptionThis project develops our understanding of the representation of women’s interests in politics by considering the role that men can play in advancing the substantive representation of women (SRW). I draw on the case of the United Kingdom Parliament, which over the last three decades has seen significant changes in the sex balance of Members of Parliament (MPs) in the House of Commons. Using quantitative analysis of two legislative activities – Early Day Motions, and the annual International Women’s Day Debates – I first establish the patterns of men’s engagement in SRW. I argue that men’s role in representation women can be understood as what I term an “ancillary representatives” for women, which is a role that draws on a vantage point not accessible to women to help advance the SRW, while also remains secondary to women’s leadership role. The role played by men remains fairly consistent over time, with some evidence of a mainstreaming of women’s issues over time as the number of women in politics increases. Then, using interview data from 30 original interviews with sitting MPs (both men and women) and analysis of transcripts of interviews carried out with women MPs in 2004, I develop the idea of men as ancillary representatives by showing that they see themselves as holding a very distinct role in the representation of women, largely as a supporter or ally for women. The findings from the interview data also reinforces and develops the existing work in the literature on women’s representation first by showing that the logic of women’s difference and the importance of life experience in shaping the perspective of women in politics also applies in the case of men; and second by showing that an additional often unseen impact of women in politics is that they have the ability to also influence their male colleagues.