Chief executive says increase in national insurance contributions could mean more expensive groceries

Food sales at Sainsbury’s have been boosted by a return to the office and fewer people dining out in restaurants, as the retailer warned of possible price rises as a result of having to pay £140m more next year in national insurance contributions [NICs].

The supermarket chain’s pre-tax profits were £356m for the six months to mid-September, up 4.7% on the same period last year, driven by a 5% increase in sales in its grocery business.