John Lewis: The chain that will never be knowingly undersold (in an 8 mile radius)

But now John Lewis is bowing to the inevitable and radically changing its pledge never to be beaten on price.

The chain's famous motto of 'never knowingly undersold' will in future be limited to matching the prices of rivals within eight miles of the department store.

In addition, the rival must be a 'bricks and mortar' business rather than an internet trader. John Lewis said Its hand was forced by competition from cheap discount warehouses and out-of-town outlets, which have much lower overheads.

Its price promise, which dates back to 1925, meant shoppers were offered a refund of the difference on a product found cheaper elsewhere.

The firm even sent out teams of price checkers to ensure customers got the best deal on everything from dishwashers to sofas. Now in a pilot scheme involving stores in Aberdeen, Edinburgh and Glasgow, these checks will be limited to rivals nearby.

Leigh Sparks, professor of retail studies at the University of Stirling, said: "I am not sure how many people have had to use the promise. But the fact that it is there has created a positive image, reputation and trusted persona for the brand."

Many shoppers believed the price promise was a cast-iron pledge to match any price at any other store in the country.

But John Lewis insisted yesterday that there have always been geographical limits, with 13 stores already limiting price checks to four miles.

A spokesman added: "Never knowingly undersold is a unique concept.

"It is different to price promises by other retailers as we check prices at competitors and reduce our prices for our customers."

John Lewis has never tried to match prices for goods sold by internet rivals, saying it chooses to compete with retail websites by offering better sales and after-sales service.