Sainsbury’s has upgraded its profit expectations by £60m after surging sales of champagne, steaks and other luxury food drove stronger than expected sales over Christmas and new year. The UK’s second largest supermarket reported that like-for-like sales jumped by a stronger-than-expected 9.3% year-on-year during its Christmas period, from 1 November through to 2 January. Supermarkets have been one of the main beneficiaries of consumer spending.