Highlights
- Asda's regular prices cheaper than Tesco Clubcard and Nectar card deals.
- Basket of 240 branded items cost £795 at Asda versus £912 at Tesco.
- Some products priced 125 per cent higher at competitors without loyalty cards.
A study of 240 branded products, including Dolmio Bolognese Sauce, Nescafe Azera instant coffee and Mr Kipling Angel Cake Slices, came to £795.21 at Asda.
For shoppers without loyalty cards, Sainsbury's was 17 per cent more expensive, while Tesco's basket reached £912.56, which is 15 per cent higher.
Asda does not offer special prices to its Asda Rewards members, meaning all customers pay the same price.
This made Britain's two biggest supermarkets more expensive than Waitrose (£895.28) for branded items for non-loyalty card holders for the third month running.
The biggest price difference in April was Colgate Plax Cool Mint Mouthwash 500ml, which cost £2 at Asda but £4.50 at both Tesco and Sainsbury's without a loyalty card, a 125 per cent gap.
A 50-pack of Pampers Premium Protection New Baby Diapers cost £4.54 with a Tesco Clubcard but £8.70 for those without, showing a 92 per cent difference.
Loyalty card impact
Even with loyalty cards, Asda stayed cheaper. The same basket cost £821.67 with a Tesco Clubcard (3 per cent more than Asda) and £850.39 with a Nectar card (6 per cent more).
Morrisons was 5 per cent more expensive with a More card (£838.15) and 6 per cent more costly without one (£839.18).
Which? found Waitrose offered the lowest prices on several products. Dolmio Bolognese Sauce Onion And Garlic 450g cost £1.50 at Waitrose compared with £2.60 at most other supermarkets for non-loyalty card holders, a 73 per cent difference.
Sharwood's Medium Egg Noodles 226g was £1.36 at Waitrose but £2.10 at Tesco for non-members, a 54 per cent gap.
Which? retail editor Reena Sewraz said: "Our latest analysis shows Asda continues to offer the lowest prices on branded groceries without shoppers needing a loyalty card.
In some cases, consumers are paying double for identical products depending on where they shop and whether they have a loyalty card."
A Sainsbury's spokesperson said that 85 per cent of sales involve a Nectar card, while Tesco noted that Clubcard "unlocks the biggest savings" alongside their Aldi Price Match scheme.
Aldi and Lidl were not included in the study because they do not stock enough branded groceries.
