Tesco has been rapped by the Advertising Standards Authority (ASA) for promotions that used an "unfair" selection of goods to claim that a trolley of shopping at its supermarkets was significantly cheaper than rivals, Asda and Wm Morrison.

The regulator today ruled that Tesco must no longer display the print advertisements in their current form because some of the products used to compare prices were on special discount at the time.

The first advert showed a shopping trolley full of goods, stating: "Asda £76.15, Tesco £49.59. Why pay more at Asda?", and used the disclaimer: "Includes Tesco products on promotion".

The second promotion claimed a £25.52 differential with Morrisons, and said: "Save a trolley-load of cash at Tesco".

Having received two complaints, the ASA ruled that the adverts conveyed a false impression that Tesco was generally cheaper and were likely to mislead consumers.

The ASA said the comparisons had been made between an "unfair selection of goods" and "both ads were likely to mislead".

The regulator said: "Although we noted both ads clearly stated 'Includes Tesco products on promotion', we considered that that disclaimer did not go far enough to remove the implication given by the headline claims that Tesco was generally cheaper than either of their competitors.

"Nor did we consider that it explained adequately to consumers that the savings were representative of a comparison between promotional prices and everyday prices and could only be achieved for a limited time; they were therefore not representative of the savings consumers could generally expect from Tesco."

The regulator noted that Tesco had sent copies of till receipts to show that the prices were correct on the days stated.

"Tesco explained that the ads were not: intended to represent a shopping basket survey; to demonstrate a typical and representative selection of consumer goods; or illustrate a comprehensive survey of prices.

"They said the ads made comparisons between a number of named products and, in their view, provided a snapshot of the savings that customers could make by buying clearly identified, specific products at Tesco rather than from their competitors."

A spokeswoman at Tesco said: "Tesco is committed to offering customers great value.

"We did state that the items were on promotion but we accept that this may not have been as clear as it could be; it does not, however, take away from the fact that we offer great prices.

"Following the ASA's concerns, all new adverts are now taking a different format."

Times Recommends

• C&G axed - 1,660 jobs to be lost
• UK house prices rise 1.1% as buyers return
• Mixed reaction to US banks repaying bailouts