A complaint by Asda about Aldi’s Swap and Save ad campaign has been upheld by the Advertising Standards Authority (ASA), after the advertising watchdog found that the ad was misleading.

The TV ad featured a woman talking about how she had saved £45 a week by swapping her usual supermarket to shop at Aldi.

Text at the bottom of the ad stated “88 out of 100 people saved. Challenge completed between 01/04/13 and 26/05/13”.

Rival grocer Asda complained that the campaign was misleading, arguing that the type of products, including price promotions and product size, included in the comparison could not be verified and the data period mentioned in the ad was out of date and invalid for a price sensitive market.

In its defence, Aldi said to make sure the comparison of purchases was as fair as possible, items were excluded that could not be bought from the core Aldi range such as clothing and DVDs, special pharmacy items and high ticket “special items” such as spirits.

Regarding the advert showcasing price information from between April to May, Aldi said that because a campaign like this took time to complete, the data-set would inevitably be less than fully current. They also said their prices had not changed significantly since April/May.

The ASA said: “We told Aldi Stores to ensure that the basis for comparisons were made clear in their future ads and that they should be able to provide substantiation for any savings claims made on the basis of these comparisons. We also told them that, in order to make the comparison verifiable, they should amend the ad to include either a postal address to which viewers could write for full details of the comparison, including which products were included and at what prices, or a web address that linked directly to a page about the campaign that included such details or a postal address.”

A spokeswoman for Aldi said: “We are wholly disappointed by the ASA’s decision. We worked with Clearcast to ensure compliance with current BIS pricing and BCAP codes of practice. The Swap & Save adverts are based on the actual savings of shoppers and the overall advertising message remains true; you can save money by swapping to do your weekly shop at Aldi.

“It is no surprise that other supermarkets are trying to find issue with our campaign as we continue to impress shoppers with both the price and quality of what we sell. Aldi recently came top in Which? Magazine’s Customer Satisfaction Survey and was the only supermarket to score five stars out of five for pricing. Our Swap & Save advertising features real people who are benefitting from our low prices which provide them with genuine financial savings when swapping to do their weekly shop at Aldi.”

A spokeswoman for Asda said: “Our customers are at the heart of everything we do, so when we see something which attempts to pull the wool over their eyes we naturally want to set the record straight.”

The ASA banned the ad in its current form.

Aldi's "Swap and Save" ad has been upheld by the ASA