Asda has been knocked off the top spot as the cheapest supermarket for a ‘big shop’ for the first time in more than three years.

Since January 2020, Asda has remained the most reasonably priced for larger households wishing to fill their trolley with over 130 items including some big brand favourites.

But after more than 40 months in first place, Morrisons has knocked it into second place – with a difference of 22p.

To reach its conclusion Which? compared the total cost of 135 popular grocery items at six supermarkets with the shopping list including big brands such as Andrex toilet paper and Cathedral City cheese.

Budget supermarkets such as Lidl and Aldi were excluded from the research because they don't always stock such brands, says the consumer group.

Which? found Morrisons to be the cheapest last month where it cost £341.92 for the trolley load. At Asda the same items came in at £342.14.

When comparing a smaller basket of less than 40 items, as it also does monthly, Which? found Aldi to be the UK’s cheapest supermarket for July.

Fellow discounter Lidl, who had also been included in the basket-based research, was just behind Aldi with a difference of £1.38 and a shop costing £72.60.

Waitrose was the most expensive last month with a basket of groceries costing £87.24, which is 22% more than Aldi and a difference of £16.02.

For the 135 trolley items – the shop at Waitrose would have cost £376.66 – £34 more expensive than winner Morrisons.

This latest pricing analysis, says Which?, demonstrates that shoppers can make savings on their groceries depending on where they choose to buy their food. But the consumer group maintains there is still more work for supermarkets to do.

Natalie Hitchins, Which? Head of Home Products and Services, explained: “Households up and down the country are having their budgets squeezed by the cost of living crisis and our latest research shows that once again Aldi is the cheapest supermarket.

“For a larger trolley of items, Asda has been knocked off its perch as the cheapest option for the first time in several years with Morrison pipping it to the post for value.

“Which? believes that supermarkets are currently failing to adequately help shoppers during the current crisis. They must ensure everyone has easy access to basic, affordable food ranges at a store near them – including providing a range of essential budget lines that support a healthy diet in smaller convenience stores where they have them. They must also provide transparent and comparable pricing so people can easily work out which products offer the best value.”