Supermarket key items such as pasta, tinned tomatoes and strawberry jam increased in price by around eight per cent in just one year, according to the latest figures.
Assosia, a retail research firm, tracked the average cost of staple food products at Asda, Morrisons, Sainsbury's and Tesco.
The company recorded more than 17,000 price increases across the 'big four' supermarkets in January, more than double the number in the same month last year, and across every category.
