Data on ethnicity has been collected by the UK's decennial Census since 1991. Examination of data for the main metropolitan areas led some commentators to conclude that while segregation by ethnicity and class existed, the levels were relatively low in comparison with those found in the US. In 2005, however, Trevor Phillips (at the time head of the Commission for Racial Equality) warned that the UK's pursuit of multiracial policies meant that the country was 'sleepwalking to segregation'. Using the results of the 1991, 2001 and 2011 Censuses, for ethnic groups and social classes, this paper examines changing patterns of segregation in Greater London at a number of different scales. It will show that while it is possible to argue that segregation has increased and decreased according to the level of analysis and the different groups under examination, combined ethnic and social class analysis points to persistently high levels of segregation among certain groups.