Widening participation initiatives tend to focus on raising the aspirations of the working class rather than changing educational cultures. However, any analysis must take account of the role of the educational institution itself in creating and perpetuating inequalities. Participation in higher education (HE) is an inherently more risky, costly and uncertain "choice" for working class groups and this frames their decisions. This paper focuses on the particular issues and "risks" raised when mature working-class students form a small minority in an elite institution. It draws on the experiences of two cohorts of mature students to examine the contrasting discourses used to explain their exclusion and choice. It argues that if the entrenched inequalities in participation in, and across, HE are to be properly addressed and systematically dismantled, there is a need to understand issues of process and structure, and exclusion and choice, in all their complexity.