Conventional political wisdom has it that educational expansion helps to reduce socioeconomic inequalities of access to education by increasing equality of educational opportunity. The counterarguments of Maximally Maintained Inequality (MMI) and Effectively Maintained Inequality (EMI), in contrast, contend that educational inequalities tend to persist despite expansion because those from more advantaged social class backgrounds are better placed to take up the new educational opportunities that expansion affords (MMI) and to secure for themselves qualitatively better kinds of education at any given level (EMI). This paper sets out to test the predictions of the MMI and EMI hypotheses against empirical data for the case of Britain where higher education expanded dramatically during the 1960s and again during the early 1990s. The results show that quantitative inequalities between social classes in the odds of higher education enrolment proved remarkably persistent for much of the period between 1960 and 1995, and began to decline only during the early 1990s, after the enrolment rate for the most advantaged social class had reached saturation point. Throughout this same 35 year period, qualitative inequalities between social classes in the odds of enrolment on more traditional and higher status degree programmes and at "Old" universities remained fundamentally unchanged. In short, social class inequalities in British higher education have been both maximally and effectively maintained.