Retail sales fell by 1.8% last month - the largest monthly fall since January 2003, according to the Office for National Statistics.

The fall came as a shock to analysts who had expected a small increase.

"We would urge retailers to keep a sense of perspective and not to start predicting gloom and doom just yet,” said David Bush, head of the retail services team at Grant Thornton. “January is traditionally the quietest month for sales and this year's results are still a healthy 3.3% higher than this time last year."