Almost 80 per cent of the capital’s 253 museums and galleries were questioned for Holding up the mirror, a report for the London Museums Agency. It revealed an uneven awareness of cultural diversity among managers. Many institutions failed to recognise the barriers between them and local communities.

The report said effective diversity work was often the result of one enthusiastic individual and was often abandoned when they moved on. The association has commissioned another report, examining how communities would like to see their needs reflected.

Lee Jasper, adviser to London mayor Ken Livingstone, said: “Too often in museums, black people are relegated to the position of slaves in some Renaissance painting. There’s a cultural ethnic cleansing that leaves young people devoid of any sense of history. If museums want to attract younger, more diverse audiences, they have to reflect their histories.”

Holding up the mirror is published on July 31. www.londonmuseums.org