A new study has revealed how shoppers can save almost £25 topping up their supplies at budget chains instead of the major supermarkets - including the notoriously cheap Aldi and Lidl.

Nielsen said the comparison was based on how much shoppers splash out when buying at least 20 items rather than a like-for-like basket.

The cost of 20 everyday items like batteries, tea and soft drinks comes to £31.28 at stores like Poundland and B&M compared with £55.85 at Sainsbury’s.

If you choose instead to shop at Aldi and Lidl you can get more than £15 off the bill compared with a Sainsbury’s and Tesco shop.

Research by market analysts Nielsen into the shopping habits of 15,000 households shows Brits who use bargain chains spend less than when filling baskets at the leading stores.

Average spend when shopping basket over 20 items

Nielsen Homescan

A Nielsen spokesman said it was an insight into how Brits tailor their shopping needs according to the store.

He added: “Discounters carry a range of up to 2,000 lines, whereas larger supermarkets carry a range of 25,000 to 30,000 items, from value to premium lines.

“And, therefore, shoppers generally purchase private label items from discounters whereas purchases from larger supermarkets contain a wider range of items, from private label to brand to premium.”

Upmarket chain Waitrose was the most expensive for a so-called “big shop” of 20 products, with a bill of £58.85 followed by Marks and Spencer with £58.19 - more than £25 dearer than the value-for-money chains.

Lidl was the cheapest discounter, £38.41 compared with Aldi at £39.11.

Surprisingly, the study found at £42.10 the Co-op was cheaper for 20 items than Iceland where a big shop cost £49.16.

Out of the Big Four, Morrisons had the cheapest basket at £51.65, followed by Asda at £51.73, Tesco with £53.39 and Sainsbury’s with £55.85.

Morrisons slammed the study as “misleading” and said it was not a like-for-like comparison.

A Sainsbury's spokeswoman said: "We don't believe the methodology used offers a true comparison and can reassure our customers we always aim to deliver the best quality and value."

Nielsen's spokesman added: "In simple terms, when people do a big shop at the discounters they spend £15 less than they do at one at the big four, as the shopping basket from a discounter contains a different range of products with more private label."