Last week, a lady named Christine Tacon added to Tesco’s long list of woes. Ms Tacon is, in effect, Britain’s retail ombudsman, though her official title is ‘groceries code adjudicator.’

Tesco, Britain’s biggest supermarket chain, has revamped its price-match scheme to give shoppers instant reductions on branded goods at the till, the latest shot to be fired in the current price war.