Online retail sales increased by 14 per cent last year to more than £50 billion.
Shopping comparison website Kelkoo predicted a similar increase this year, well above the expected 3.65 per cent rise in total retail sales.
Online shoppers spent an average of just under £1,500 each on 39 items last year, with internet retail trade accounting for 12 per cent of total spending, the highest in Europe, said the report.
Other European countries with high online retail market shares included Germany (9 per cent), Switzerland (8.7 per cent) and Norway (8.1 per cent), while the lowest were in Italy (1.3 per cent) and Poland (3.1 per cent).
Chris Simpson of Kelkoo, said: "Over the last five years internet retailing has improved substantially thanks to the use of affordable 'always-on' internet connections, simple and secure payment systems and the increasing popularity of mobile devices, combined with the growth of mobile-based retail sites.
"All of these factors should help online retail sales and retail sales via mobile devices to continue to thrive in 2012.
"It's natural to see consumer appetite for online shopping growing year on year. This is not because people are spending more money but because they are shopping in the most convenient and affordable way for their individual needs.
"Inevitably, this will have an ongoing negative impact on the high street, an issue which is forcing retailers to bring the two channels much closer together.
"It is widely acknowledged that the recession has boosted the appeal of online retailing and UK consumers are more determined than ever to make every penny count.
"We predict that British online retailers will enjoy an average rise in online sales of 14 per cent this year."