Family food bills have surged by almost £800 a year, as food inflation forces up supermarket prices.

Staples such as breakfast cereals, milk and tea bags at the three biggest supermarkets are 15 per cent higher than a year ago and consumers must cope with the highest food inflation in a generation.

Research by price comparison site showed that a family that spent£100 a week on groceries a year ago is now paying an extra£780 a year. The site tracks prices at Tesco, Asda and Sainsbury’s and its findings were based on a basket of 24 items.

The level of inflation is seven times higher than official data shows. A BRC spokesman said that, although prices of some products are increasing, retailers are not passing the full rise on to shoppers.