The complaint is being bought by rival UK supermarket group Sainsbury's. Chief executive, Sir Peter Davis, has condemned Tesco's claims that its prices are 8% cheaper as rubbish and will take Tesco to the Advertising Standards Authority.
Tesco has admitted to raising some prices, but said they were still cheaper than in other stores. The company last week launched a £100m ongoing price-check campaign to promote its low prices.
Sainsbury's claims to be within one or two per cent of Tesco's prices. In press reports yesterday it was revealed that more than 70% of Tesco's prices went up during the week beginning September 17.
According to a Tesco spokesman, "We are convinced that our figures are right. All our price cuts are listed on the web because we want the truth to be known."
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the Advertising