Retail sales volumes in May jumped 3.9% year-on-year but dipped 0.5% on the previous month, according to the Office for National Statistics.

Sales values increased by 3.2% year-on-year but was down 0.5% on April. The average weekly spend was £7bn across the retail industry during May.

Over a three-month period, sales quantities increased 1.3%. This is the fifteenth consecutive month of growth, the longest period of sustained growth since November 2007.

Deloitte UK head of retail Ian Geddes pointed out that April’s figures were flattered by the inclusion of Easter. He said: “The real story lies in the strong year-on-year growth in retail sales. Lower inflation, positive employment numbers and a general improving economic outlook for the UK have all helped to lift overall consumer confidence.”

However, the average price of goods in May showed continued deflation, down 0.7%. Food stores were the only sector to show a price increase, rising 0.4%, but this was the lowest level since March 2006.

Online sales rose 15.1% year-on-year but only edged up 1.5% on April.

Barclay head of retail and wholesale Richard Lowe said: “May’s temperamental weather resulted in many people preferring to shop online to avoid the drizzle, with consumers splashing out on sporting goods in anticipation of the World Cup kicking off this month.”