Buyers opting for the Internet are expected to push Christmas sales on the web up 45 per cent on last year. And while that's excellent news for the growing list of Web-based firms, it means more misery on the High Street. Studies published today indicate a forthcoming boom for Internet retailers and a bust for traditional stores. Working parents with no time to wander the High Street are behind the remarkable rise in online shopping.

The convenience of browsing the web, ahead of any cost savings, is driving the change in the way we buy. Twenty-four million Britons will shop for a product or service on the Internet this year, spending around £20 billion. Christmas sales are expected to rise to around £5.22 billion - up by £1.62 billion at the same time last year. Internet shopping accounted for around 8.6 per cent of retail sales in October and is expected to grow to nine per cent over the festive season.

Electrical goods are leading the bonanza. Twenty per cent of electrical products sold this Christmas will be bought on the Internet. Digital radios and TV boxes, hair driers and straighteners, coffee machines and games consoles such as the new Microsoft Xbox and Sony's PSP top the list. For children, the remote control dinosaur Roborapter and the Darth Vader Voice Changer Helmet are already big hits.

The Internet shopping boom is revealed in a study by the Interactive Media in Retail Group, the industry body for so-called "e-tailers". A second study from accountants Deloitte identifies the grim picture for bricks-and-mortar stores, which have reported poor trading for seven months in a row. The firm predicts total spending on Christmas gifts this year will fall by around £400 million - the first decline in a decade. This will, apparently, be entirely shouldered by traditional stores. It said the average amount spent on gifts per person will be £310, down 2.8 per cent on 2004.

"Predictions of High Street carnage this year could be closer to the truth than first expected", it warned. Last year, many of those who opted for the Internet faced disappointment when parcels did not arrive on time for Christmas. As a result, some retailers have brought forward their last order dates this year. Others have employed more people in their order and delivery departments. However, at least one leading industry group suggests many have failed to prepare for the rush.

An estimated 100 million parcels ordered on the Internet will need to be shipped in the run-up to December 25. Last year Royal Mail delivered only 66.1 per cent of this mail on time between December 1 and 21. Paul Dawson, of IT experts Conchango, said Internet retailers risk developing a reputation for failing to deliver on their promises. "There's nothing that will damage corporate reputation more than a young child staring forlornly at an empty stocking on Christmas Day".