They deliberately misled customers and have now been found out

Sir Peter Davis, Sainsbury's

Tesco has been told to seek advice before considering similar advertising, but maintains its claims that it is cheaper.

In the first leaflet, Tesco said it was 16% cheaper than its rival based on a weekly shop carried out at a Sainsbury's store in London in March this year.

The second, based on the same theme, said Tesco was 13% cheaper and showed a picture of two till receipts.

Selected brands

The ASA upheld both complaints from Sainsbury's and asked Tesco to seek advice from the Committee of Advertising Practice before producing any similar price comparisons.

Chief executive for Sainsbury's Sir Peter Davis said: "Customers should know that this type of advertising, comparing small samples of products, cannot be trusted.

"Tesco selectively chose products on 'special offer' at Tesco but not Sainsbury's.

"They deliberately misled customers and have now been found out."

In response, a Tesco spokesman said: "We accept that the design of these local leaflets could have given customers the impression that Tesco was on average 13% and 16% cheaper than Sainsbury's, when in fact we are on average 8% cheaper.

"The leaflets are no longer being used."