Which? found shoppers could save more than £16 on a basket of items at Aldi last month compared to the most expensive supermarket Waitrose.

The consumer champion’s analysis involved comparing the average prices of a shop consisting of popular groceries at eight of the UK’s biggest supermarkets. It carries out the same study each month.

The cheapest supermarket for June was Aldi, where a basket of goods cost £75.25 on average across the month.

The seven remaining supermarkets’ basket of goods cost:

• Lidl £77.18
• Asda £82.55
• Tesco £82.67
• Sainsbury’s £83.46
• Morrisons £85.98
• Ocado £89.20
• Waitrose £91.80

Asda is cheapest for a largest trolley

Which? also compared the cost of a larger trolley of 134 items – the original 42, plus 92 more. These items included a larger number of branded items, such as Andrex toilet paper and Cathedral City cheese. But this analysis did not include budget supermarkets Aldi and Lidl, as they do not always stock some of these products.

In June, Asda was the cheapest for this larger trolley of groceries, a title it has held since January 2020. In June 2023, it cost £333.16 on average for this shop, beating the next cheapest, Morrisons (£343.41), by £10.25. Waitrose was £36.73 more expensive than Asda, coming in at £369.89 on average.

Calls for supermarkets to do more to help consumers

This latest pricing analysis from Which? demonstrates that shoppers can make considerable savings on their groceries depending on where they buy their food.

However, Which? noted that even budget ranges at Lidl and Aldi are rising in price significantly, while traditional supermarkets’ convenience stores often fail to offer or stock budget lines.

The consumer group accused supermarkets of not doing enough to support their customers during the cost-of-living crisis. It has called for the big supermarkets to ensure their smaller convenience stores stock a range of essential budget lines that support a healthy diet. It also said that unit pricing needs to be clearer so that customers can easily work out the best value products.

While some of the supermarkets have engaged with the consumer champion as part of its Affordable Food For All campaign, Which? said action to date has been “severely limited”.

Ele Clark, Which? retail editor, said: “Millions of people are struggling during the worst cost-of-living crisis in decades, and Which?’s research shows why many shoppers are turning to discounters like Aldi and Lidl.

“Which? believes that supermarkets are currently falling short when it comes to helping shoppers. They have a responsibility to ensure everyone has easy access to basic, affordable food ranges at a store near them, and to provide transparent and comparable pricing so people can easily work out which products offer the best value.”