In a political context, the ‘glass ceiling’ is shorthand for the barriers faced by women politicians, resulting in them being less likely to reach executive roles at the same rate as their male colleagues. This article outlines a case where there was sex equality in executive appointments; a cohort study of British Labour Party MPs elected at the 1997 parliamentary election. Examining executive appointments at the cabinet and sub-cabinet level, descriptive analysis shows no statistically significant differences in the proportion of men and women reaching executive positions, or the prestige and gender type of these positions. Regression modelling confirms this, and sex is not found to be a significant driver of these patterns. Three factors are identified that combined to achieve this – critical actors, favourable context and a left-wing party in government. The article concludes with a call for further comparative research using the cohort study method.