How surprising to read one former Tesco chief, 82-year-old Lord MacLaurin, badmouthing another, Sir Terry Leahy. The surprise is because both were titans of their trade and Leahy has always been seen as Ian MacLaurin’s protégé: it was MacLaurin who took Tesco to the top of the UK supermarket league in the mid-1990s, then Leahy who quadrupled its sales, profits and share price between 1997 and 2011 to make it the monster we know.