Sainsbury's is taking its battle against Tesco's Price Promise campaign into the courtroom, by requesting a judicial review against a ruling by the Advertising Standards Authority that rejected its complaint over the Tesco pledge.
Sainsbury's commercial director Mike Coupe said it was "time to take a stand" on the row over the Tesco Price Promise, which the supermarket believes does not offer a fair comparison.
Mr Coupe said:
"Tesco says that whether, for example, a product is Fairtrade or MSC [Marine Stewardship Council] certified is just a 'minor part' of a customer's considerations - especially for value products. We disagree.
More than ever, customers want to let their values guide them and in price-matching its products with ours, Tesco is - when it sees fit - choosing to ignore factors such as ethical or provenance certification or even country of origin.
The Tesco Price Promise is a money-back pledge that compares the price of goods in a shopper's trolley at the checkout with prices at rival supermarkets Asda, Sainsbury's and Morrisons.
Any difference on comparable products is then refunded in the form of a Tesco voucher worth up to £10.
Sainsbury's believes the pledge misleads consumers because it does not make fair comparisons by, for example, matching products such as its Everyday Value Tea, which is not Fairtrade, with Sainsbury's basics tea, which is.
It added the pledge is also misleading on its basics water, which comes from a spring in Yorkshire, and is compared with Tesco's Everyday Value water, which Sainsbury's claims starts at the mains supply.
Sainsbury's is stepping up its fight against Tesco's Price Promise campaign in a long-running row over comparisons between the two firm's products.
Britain's third-biggest supermarket chain is to take its battle into the courtroom, by requesting a judicial review against a ruling by the Advertising Standards Authority (ASA) that rejected its complaint over the Tesco pledge.
The move comes after Sainsbury's lost an appeal against the ASA decision earlier this month, when a report by the watchdog's independent reviewer Sir Hayden Philips backed the ASA findings.
Mike Coupe, Sainsbury's commercial director, said it was "time to take a stand" on behalf of customers to ensure shopping decisions are not just based on price, but also factors such as ethics and provenance.