Asda is putting its money where its mouth is with a guarantee that it offers shoppers lowest prices on groceries or will give them their money back, a step which it said “heralds the official end of the grocery price war”.

Asda has launched Asda Price Guarantee, which it said is a “cast-iron promise to shoppers that it cannot, and will not, be beaten on price”.

The Asda Price Guarantee allows shoppers the chance to go online at the day after their shop to compare the prices of the same products from its receipt information at rivals Tesco, Sainsbury’s and Morrisons.

The grocer said if shoppers can purchase a basket of eight or more comparable products cheaper elsewhere, it will refund the difference, plus a penny more “for good measure”.

The price checker is powered by online comparison site

Asda chief executive Andy Bond said the move is “a watershed moment in the history of Asda”.

He said: “From today, Asda cannot, and will not, be beaten on price. Our grocery guarantee puts an end to the phoney price wars that most shoppers are sick of. Plain and simple, our Price Guarantee is our cast iron promise that your basket of shopping will always be cheapest at Asda.

“And for the millions of shoppers who go elsewhere, my challenge is this – come to Asda this weekend and see for yourselves how much you’d save.”

Asda said the Asda Price Guarantee “heralds the official end of the grocery price war” and uses a worldwide first in harnessing the internet to guarantee the lowest price to customers. It covers 13,000 branded and own-brand products, and items on promotion. will compare like-for-like branded or own label groceries, accounting for 70% of all grocery sales at Asda.

Around 10% of products at Asda are unique to the store and not included. The remaining 20% could be comparable but are not because of trading standards regulations around the weight of packets.

Non-grocery categories are currently not covered in the Asda Price Guarantee.