This article focuses on the effects and limits of equality and diversity policies developed by two main English trade unions – gmb and unison. Over the past 15 years, pushed by ethical and also strategic issues, most trade unions in England have adopted radical measures in order to dismantle internal mechanisms that (re)produce gender inequalities. In the most feminised unions, these measures (proportionality and reserved seats) have allowed some white and qualified women to climb the union hierarchy ladder. At the same time some self-organised groups have also tried to empower other constituencies underrepresented in union structures, such as black and ethnic minorities, or Lesbians, Gays, Bisexuals, Transsexuals (lgbt). This qualitative research based on life-story interviews highlights the persistence of a glass ceiling and the under-estimation of inequalities between women.