The price of a shopping basket containing 24 staple items of food has increased by an average of 21 per cent year on year, according to online price comparison site Mysupermarket.co.uk.

Based on a family of four’s weekly shop in June this year, compared with June last year, the increase means that if a family spends£100 a week, this is a price hike of£1,092 a year. Most of the items – including bread, bananas, eggs, cheese and pasta – were own-branded where possible to make it a fair comparison of the three supermarkets, Tesco, Asda and Sainsbury’s.

“Once again, we’re seeing a significant price increase in shopper’s staple items,” said Johnny Stern, a director at Mysupermarket.co.uk. “Unfortunately, prices of staples overall are going up, although elsewhere in the supermarket, there are some product prices that have been cut. We would advise shoppers trying to stick to a tight budget to look out for better-priced like-for-like items and special offers within the supermarket you already shop at – there are significant and regular savings to be had to combat the crunch.”

The biggest price rises continued to be on dairy and wheat-based products, with fruit and vegetables catching up fast. This month, Tesco proved it was the cheapest of the three supermarkets, because of several special promotions and price cuts.