Sainsbury’s, which uses celebrity chef Jamie Oliver as its figurehead, is expected to reveal that like-for-like sales figures, excluding new store openings, are up by between 3.5 and 4 per cent for its past quarter of trading.

This contributes to an estimated first-half sales growth of 8 per cent, once new stores are factored in.

Tesco last week reported a second-quarter, like-for-like increase of 4 per cent, confirming that customers are increasing their spend on groceries and other supermarket items.

However,  supermarket sales increases are due more to inflation than customers buying more items, analysts at Credit Suisse said.

This week Sainsbury’s will also up the stakes in the war for supermarket clothing spend by revealing it has poached rival George at Asda’s buying director, Sara Bradley, to lead product development at its fashion label Tu.

The collapse into administration of fashion retailers Joy and Miss Sixty last week shows it is becoming harder for smaller retailers to compete against bigger chains.