Report reveals shoppers' £46bn spree on the net

That equates to 15p in every £1 of retail spending in the UK, according to the Interactive Media in Retail Group.

Electrical goods were among the most popular online sectors, with December sales up 60 per cent from the same period in 2006.

The boom in online trade contrasts with the flat Christmas experienced by many high street retailers.

Some four million shopped on the Internet on Christmas Day alone, spending an estimated total of £84million, according to the study.

This boost was mainly due to high street giants such as Marks & Spencer, Comet and Dixons launching their sales online that day.

The joint report by IMRG and analysts Capgemini tracked online sales for goods such as groceries, clothes, electricals, tickets, travel and digital downloads using data from 60 major Internet retailers.

IMRG boss James Roper said traditional retailers who did not sell online were losing out.

He said: "Virtually all the growth in retail is now online. There is no growth anywhere else and it is taking more and more business from the high street to online channels.

"The Internet has become the dynamo of retail - it is where all the growth is now."

However, the report's figures for online spending were more than double those given by the British Retail Consortium.

Consortium spokesman Krishan Rama said: "The IMRG figures are always higher because they include a range of things which aren't actually retail spending, like holidays.

"Obviously Internet spending is growing rapidly but still only represents 6 per cent of retail sales."