It hired one group of consultants just before Christmas. But they backed out after deciding they wanted the firm's name not to be disclosed in the report as the OFT had planned. Officials were forced to hire a second firm, wasting two weeks' work and pushing the report publication close to the February deadline. The OFT is due to meet the big four supermarket groups in the next two weeks as its investigation reaches its closing stages. OFT officials will present their initial findings to Tesco, Sainsbury, Asda and Safeway and seek their comments before publishing the final report.
The OFT is using a complex economic model which has been criticised as being "one-dimensional" and ignoring what many regard as the key issue, which is whether the bulk buying discounts superstores receive from suppliers are passed on to customers.
Privately, supermarkets are resigned to a wider investigation being recommended by the OFT and a possible referral to the Monopolies and Mergers Commission. It is understood the OFT has taken the view that although consumers may pay higher prices for some items in supermarkets compared with local grocers and other shops, they are willing to pay for the convenience of doing all their shopping under one roof. But the strength of the prices campaign is likely to lead to a more detailed examination, supermarkets say.