Latest figures from the BRC-Nielsen Shop Price Index show that overall shop prices saw deflation of 1.9% in May, unchanged from April and the 25th straight month of decline.

Food prices were down 0.9%, also unchanged from the previous month, although fresh food prices slid 1.9%, their sharpest fall since the survey started in 2006. Non-food deflation remained at 2.5% in May, meaning prices in the sector have now fallen for over three years.

Mike Watkins, Head of Retailer and Business Insight, Nielsen, said: "Retailers continue to use price cuts and promotions to stimulate sales which is helping to maintain shop price deflation, and we see little evidence to suggest that prices will rise in the near future. With many food retailers still using price cuts to attract new shoppers, this is lowering the cost of the weekly shop and so the overall CPI figure in the UK. Deflation and price led competition will continue to be a key driver of sales growth for some time yet."