Sales were up by 2.1 per cent in the three months from April to June compared with the same period last year. This represented a 0.9 per cent increase on May's three-monthly figure.
It is the fifth consecutive month of month-on-month growth and the highest rate of growth since May 2002.
Ernst & Young director of retail Tim Sleep said: '[These figures] represent a better performance than expected but, arguably, portrays a slightly artificial picture. The trading environment remains tough. We see no underlying change in consumer confidence.'