E-commerce trade body IRMG has urged online retailers to prepare for a huge web shopping day on 6 December.
Online shopping has been gathering momentum over the past few days after a 'Manic Monday' on 29 November, and is expected to reach a peak next week.
UK consumers are likely to spend £500m on 5 and 6 December, in what IMRG terms 'Super Sunday' and 'Mega Monday'.
Sales have been increasing steadily since 28 November, and hit a peak on 1 December, which was contrary to suggestions from other firms that last Monday would win out.
"2010 looks set to be another bumper online year, with sales for Super Sunday and Mega Monday estimated to reach over £500m at the end of a week when the festive spend really kicks in," said David Smith, managing director at IMRG.
Sales for November and December will hit £12.4bn as shoppers look to spread the cost of Christmas across the two months.
Smith reiterated his statements that the first Monday in December is usually the biggest money earner, a suggestion supported by price comparison site PriceRunner, which said that retailers will slash prices to make the most of the bumper day.
Online shoppers are likely to get the best deals yet as retailers gear up to launch discounts in a major bid to gain sales, according to Marc Thomas, UK manager at PriceRunner.
"We are seeing retailers increasing product discounts by up to 50 per cent to coincide with the anticipated shopping frenzy," he said.
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