The number of customers using Asda's notorious Price Guarantee has increased fivefold to several hundred thousand since its relaunch in January, it claims.

In the week the ASA threw out a Sainsbury's complaint against the guarantee and banned a Tesco advert, Asda said it wanted to celebrate the success of the website which now promises shoppers a voucher for the difference if the shop isn't 10% cheaper rather than continuing its acrimonious public spat with Tesco over the guarantee.

"There is no tit for tat from us," an Asda spokesman said. "People keep trying to goad us into a spat but we just rise above it. All we care about is, 'do customers find the APG helpful and do they like it?' And the answer is yes."

Asda had no plans to mark the first anniversary of the APG on 28 April, he added. "It's tempting to do short-term stunts but it is truer to our brand to have a clear promise for our customers that we are cheaper. It smooths out all of those fluctuations of high-low and special offers."

Sainsbury's claimed an Asda TV ad for the guarantee was misleading because the guarantee excluded a number of "everyday" products. However, the ASA gave the ad a clean bill of health.

Tesco's press ad showed 20 fresh produce items that it suggested were not included in the guarantee, with the strap: 'One place you won't find your fresh food for the weekend? In the Asda Price Guarantee'. However, Asda demonstrated 13 of the 20 were included.