Aldi was the cheapest supermarket in the UK in January

Their monthly analysis, which involves comparing the average price of a shop across eight of the UK’s biggest supermarkets, found Aldi was the cheapest supermarket for the shopping list of 100 items.

The groceries from Aldi cost £185.83 on average across the month.

Fellow discounter Lidl was close behind Aldi in January, costing only 76p more with the supermarket’s loyalty scheme Lidl Plus and 79p more without (£186.59/£186.62 on average).

This month, for a bigger shop of 210 items, Asda has beaten Tesco with a Clubcard and regained its place as one of the UK’s cheapest supermarkets.

Aldi and Lidl are not included in this comparison as they have a smaller range of products compared to the other supermarkets.

Asda came out cheapest at £518.90, beating Tesco with a Clubcard by £10.11 (£529.01). Asda’s return to the top spot for the longer shopping list comes just days after it announced it was dropping its Aldi and Lidl price match scheme.

The supermarket, which saw sales fall in the run-up to Christmas, has instead brought back Rollback pricing - claiming to have slashed the prices of more than 4,000 products in-store and online by an average of 25%.

Waitrose was the most expensive on average, with the bigger shop costing £592.34.

Waitrose was the most expensive supermarket for a smaller list of items this month too, totalling £242.91 on average - a difference of £57.08 compared to Aldi - 31% more.

The list of 100 items 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 £207.66 on average - while without a Clubcard, the Tesco shop cost £213.14.

For those using a Sainsbury’s Nectar card, January’s shopping list of items averaged £214.04, which is £28.21 more than at Aldi. Without a Nectar card, the same items at Sainsbury’s cost £223.84.

Reena Sewraz, Which? Retail Editor, said: “Our latest monthly analysis once again sees Aldi crowned as the UK’s cheapest supermarket, however, Lidl remains hot on its rival’s heels. Asda has also made up some ground after slipping back in our rankings in recent months.

“With people still feeling the effects of food inflation, they are likely looking to cut costs where they can. Our analysis shows that by switching supermarkets consumers could save up to 23%, highlighting the advantages of shopping around where possible."