"On core commodities, we have to be more competitive and so we will need to make our business more efficient in order to be able to do that," he told BBC television on Wednesday.

"Our prices in core commodity areas will come down over a period of time, not overnight because there's lots of work to be done to make sure we can afford to do that but we will seek to reduce prices throughout our organisation."

Asked if he was asked to quit following the regulatory blocking of the deal, Coupe said: "No I wasn't."

"In straightforward terms the board's been very supportive and so I've committed my future to Sainsbury's and will continue to do the best job I can to make sure we do a brilliant job of serving our customers week in week out," he said.

(Reporting by Paul Sandle; editing by Kate Holton)