The first shopping trend of the year has been identified by Morrisons, with the retailer suggesting that more Brits than ever are bringing their lunch to the office.

Sales of plastic storage boxes had rocketed by 260% so far in January, the supermarket chain said. It claimed this was due to “cash-conscious customers taking lunch to work”. Morrisons revealed the figures on ‘blue’ Monday - supposedly the most depressing day of the year as people begin to run out of money post-Christmas and start to receive credit card bills.

The retailer said there had been a run on comfort foods, which it also linked to a colder spell of weather. Potato sales rose 31% last week, soup was up 25% and pies and pastries were up 24%.

“Eating habits haven’t changed much between autumn and early winter but the sudden cold weather seems to have given customers a taste for comfort food, and stews are now back in fashion,” said Morrisons corporate services director Martyn Jones.