Tesco has squared up to Asda by taking out double-page spreads in several national newspapers this week, challenging Asda’s claim to be 10% cheaper than its rivals.

The ads mock the usability of the Asda Price Guarantee, claiming there are 12 steps customers need to go through to compare prices with its rivals and redeem a voucher.

It then lists 12 Tesco products that it claims are cheaper than Asda when compared on the same day.

The ads come after Tesco said at the weekend that it would complain to the Advertising Standards Authority (ASA) over what it said was Asda’s “confusing and misleading” price guarantee campaign.

The Asda Price Guarantee allows shoppers to compare the price of shopping with rivals and if it is not the cheapest by 10% customers can redeem the difference via a voucher. Tesco said the comparison was”flawed”, as it excludes about half of Tesco’s range including everyday items such as fruit, vegetables and meat.

From Monday, Tesco started accepting Asda’s refund vouchers, encouraging customers to get money off at Tesco rather than Asda.

Tesco commercial director Richard Brasher said: “We are calling on the ASA to act, and to act quickly, because in our view customers are being misled by false Asda claims.”

An Asda spokeswoman said: “Clearly the truth on pricing hurts. Our simple promise to be 10% cheaper or give customers the difference has gone down very well with customers since we launched it last week. And clearly that’s not gone unnoticed in Cheshunt.”

Tesco has begun a trial of beauty services at some of its Extra stores including nail treatments and hairdressing.