The Confederation of British Industry's retail sales monitor, conducted during the first two weeks of December, found while 22% of retailers said sales were down on a year ago, 47% said they were up.
The balance of +25% was the strongest recorded since December 2004 and exceeded expectations of just +9%.
The food and drink sector led the charge. A balance of +49% of grocers and +88% of specialist food retailers reported sales higher than a year ago.
“In the first two weeks of December, retailers' sales volumes outshone their expectations, proving good things come to those who wait,” said John Longworth, executive director of Asda and chairman of the CBI's DTS panel.
Meanwhile, TNS Worldpanel has predicted shoppers will spend a record £14.2bn on household goods over the Christmas period, with today (Thursday) and tomorrow the busiest shopping days for the supermarkets.
“Every year, the supermarkets have to strike a fine line between keeping the shelves stocked and not having too much left over that they will have to dispose of,” said Edward Garner, research director for TNS Worldpanel.
“With the biggest Christmas week ever expected this year, they need to make sure they have enough in the warehouse to service both their internet customers and those turning up to the stores.”