Britains cheapest supermarket is revealed as research shows some competitors charge a THIRD more for equivalent products

Aldi has retained its crown as Britains cheapest supermarket despite Lidl closing the gap as the discount rivals continue to gain market share, a study found today.

Consumer group Which? said the best price for a shopping list of 79 unidentified items was Aldi, where the groceries cost £133.73 on average across last month.

Its fellow German rival Lidl was close behind, costing only 67p more at £134.40 with the supermarkets loyalty scheme Lidl Plus and 70p more at £134.43 without.

Which? researched the average price of popular groceries at eight UK supermarkets - the other six being Asda, Morrisons, Ocado, Sainsburys, Tesco, and Waitrose.

For a more comprehensive list of 203 unidentified items, Asda held top spot with a total cost of £498, which beat Tesco - including with a Clubcard – at £503.03.

The study of bigger shops does not include Aldi or Lidl because they do not always stock some of the products on the consumer groups larger shopping list.

Meanwhile Waitrose was the most expensive on average, with the bigger shop costing £573.15 - a difference of £75.15 or 15 per cent more compared to Asda.

Waitrose was also the most expensive supermarket for a smaller list of items, totalling £176.41 on average - a difference of £42.68 or 32 per cent more compared to Aldi.

Consumer group Which? said the best price for a shopping list of 79 unidentified items was Aldi, where the groceries cost £133.73 on average across last month

Aldis fellow German rival Lidl was close behind, costing only 67p more at £134.40 with the supermarkets loyalty scheme Lidl Plus and 70p more at £134.43 without

While the list of 79 items was not revealed by Which?, the group said it included both branded and own-brand items, such as Birds Eye Peas, Hovis bread, milk and butter.

The analysis includes special offer prices and loyalty prices where applicable, but not multibuys.

For the smaller shop, Tesco Clubcard members would have paid £146.79 on average - but without a Clubcard, the Tesco shop cost £149.83.

For those using a Sainsburys Nectar card, Marchs list averaged £150.46, which is £16.73 more than at Aldi. Without a Nectar card, the same items at Sainsburys cost £159.24.

Reena Sewraz, Which? retail editor, said: Aldi has once again been crowned as the UKs cheapest supermarket in our monthly price analysis, however, Lidl has narrowed the gap with its rival.

It was also a strong month for Asda, as it continues to be the cheapest supermarket for a bigger list of groceries.

Shoppers are still feeling the effects of food inflation and with prices forecast to rise again, people are likely looking to cut costs where they can.

For the smaller shop, Tesco Clubcard members would have paid £146.79 on average - but without a Clubcard, the Tesco shop cost £149.83

Waitrose was the most expensive supermarket for a smaller list of items, totalling £176.41 on average - a difference of £42.68 or 32 per cent more compared to Aldi

She added that the consumer groups analysis showed consumers could pay 24 per cent less by switching supermarkets, highlighting the advantages of shopping around where possible.

Waitrose - which aims to put greater emphasis on animal welfare, ethical food standards and customer service - has been contacted for comment by MailOnline.

In January, Aldi was crowned the UKs cheapest supermarket across the whole of 2024 by Which? as well as for each of the 12 months of the year for a smaller shopping list of 56 groceries – including staples such as milk, butter, and bread.

According to the study, shoppers who stocked up at Aldi saved an average of £393 over the course of 2024, compared with those who shopped at Waitrose – the most expensive alternative.

The study also found Asda to be the cheapest supermarket in 2024 for the larger trolley of 150 items – but only for nine months of the year.

On Tuesday it was revealed by data experts at Kantar that Aldi saw its share of the UK market hit 11 per cent for the first time while its sales grew by 5.6 per cent - the chains fastest rate since last January.

Meanwhile Lidls sales rose by 9.1 per cent after attracting 385,000 more shoppers last month - more than any other grocer - to take its market share to 7.8 per cent. 

Aldi is now approaching the 35th anniversary of its first UK store opening tomorrow and is offering a £35 voucher to shoppers who share its birthday of April 5. 

Overall annual grocery price inflation was 3.5 per cent in the four weeks to March 23 - up from 3.3 per cent in both February and January, after 3.7 per cent in December.

Kantar said prices were rising fastest in chocolate confectionery, butter and spreads, and chilled smoothies and juices, and were falling fastest in dog and cat food and household paper products.