Aldi took the crown for the cheapest supermarket in July for a basket of 63 different products.
The study by Which? found that Aldi was £16.46 cheaper than Tesco and £15.94 cheaper than Sainsbury's for a comparable shopping list.
In July, the average bill for a trolley of 63 items at Aldi was £113.87.
Waitrose was found to be nearly 29 per cent more expensive than Aldi for the same products in July at £146.98 for a basket.
Aldi was the cheapest supermarket, closely followed by Lidl, and then Asda.
Which? also considered Nectar and Clubcard loyalty prices in their monthly study examining the cost of groceries and household essentials.
Sainsbury's was running Nectar price promotions on 17 items on their list
SAINSBURY'SShopping at Asda was cheaper than shopping at Tesco with a Clubcard or Sainsbury's with a Nectar card for Which?'s list of groceries.
Lidl, Morrisons and Waitrose do offer some loyalty prices to members of their schemes, but there were none for items on their shopping list this month.
Sainsbury's was running Nectar price promotions on 17 items on their list, Tesco had Clubcard prices on seven.
Asda customers could get their list of groceries cheaper (£125.61) than at Tesco with a Clubcard (£127.50).
Additionally shopping with a Sainsbury's Nectar card was slightly more expensive than Tesco with a Clubcard at £129.81.
Based on their list of 63 products, having a Clubcard would save shoppers 2.1 per cent at Tesco.
At Sainsbury's, Britons would save 3.4 per cent with a Nectar card.
For a longer list, which included more branded groceries and a bigger selection of loyalty discounts, the savings were much more substantial - i.e. 6.7 per cent at Tesco and 7.1 per cent at Sainsbury's.
Ele Clark, Which? retail editor, previously said: "With food prices continuing to squeeze household budgets, it comes as no surprise that many people are choosing to shop with the discounters, and Aldi has again won the cheapest supermarket title.
"Our analysis shows that Aldi and Lidl are still cheaper than the traditional supermarkets, even when you include loyalty pricing."
Grocery prices were 1.6 per cent higher in the four weeks to July 7, 2024, compared to the year before, according to market analyst Kantar. That's the lowest level of inflation since September 2021.
Prices are rising fastest for items such as vitamins, minerals, supplements, chilled fruit juices and drinks, and deodorants. They are falling fastest for toilet tissues, butter and dog food.
Food retailer - Average price for 63 items
- Aldi - £113.87
- Lidl - £116.24
- Asda - £125.61
- Tesco (with Clubcard) - £127.50
- Sainsbury's (with Nectar) - £129.81
- Tesco (without Clubcard) - £130.27
- Morrisons - £133.28
- Sainsbury's (without Nectar) - £134.41
- Ocado - £140.76
- Waitrose - £146.98
