In this paper we explore changes over time in higher education (HE) participation and attainment between people from richer and poorer family backgrounds during a time period when the UK higher education system expanded at a rapid rate. We use longitudinal data from three time periods to study temporal shifts in HE participation and attainment across parental income groups for children going to university in the 1970s, 1980s and 1990s. The key finding is a highly policy relevant one, namely that HE expansion has not been equally distributed across people from richer and poorer backgrounds. Rather, it has disproportionately benefited children from relatively rich families. Despite the fact that many more children from higher income backgrounds participated in HE before the recent expansion of the system, the expansion acted to widen participation gaps between rich and poor children. This finding is robust to different measures of education participation and inequality. It also emerges from non-parametric estimations and from a more detailed econometric model allowing for the sequential nature of education choices with potentially different income associations at different stages of the education sequence.