Hold on to your mouse! It's Cyber Monday

Oxford Street may have been forced to close to traffic owing to overcrowding at the weekend but today should prove to be a better day to venture out on to the high street as millions spurn the stores in favour of doing their Christmas shopping online.

Amazon, the world's largest online retailer, has predicted that today will be the now traditional "Cyber Monday". It hopes that this year's top day for online sales will match last year's, when more than 2.3 million items were bought in 24 hours.

It had been suggested that last Monday would be the big day for online retailers but the managing director of Amazon's UK division said that past experience shows that it is actually the first Monday of December.

"Mondays remain the busiest shopping day in the run-up to Christmas, but every day of that week will see high sales," added Christopher North.

He was backed up by fellow retail firms, including John Lewis which joined the British Retail Consortium in predicting that today would see the highest number of sales online.

The early spree of Christmas shopping is said to be jointly driven by a surge in spending after the last payday before Christmas, which for many people was in the past week, and fears that bad weather will affect delivery times.

Maureen Hinton, a retail analyst at the research firm Verdict, said: "We find on a weekly basis that people aren't using credit – they spend wages and savings instead. I think this weekend we'll see a big rise."

Andrew Starkey, the head of e-logistics at Interactive Media in Retail Group, forecast that £3.72bn would be spent online during the two weeks ending 12 December.

He said: "Last Monday was the first peak in the year, 5 December is expected to be bigger but, while 12 December is unlikely to fall off too much, I believe this early rise shows that consumers are becoming wary of bad weather affecting deliveries – last Christmas deliveries that were meant to take one to two days became far longer."

The weekend leading up to the expected online sales boom was a busy one on the high streets as concerns that Christmas shoppers could be crushed by overcrowding on Oxford Street in London, led to the road being closed to traffic for the second day running yesterday.

Martin Low, Westminster City Council's transport commissioner, said it was "a pre-emptive decision" to cope with the "narrower walkways" as a result of building work.

Bestsellers this year's favourite presents

The highest-selling toy on Amazon is Gamewright's Rory's Story Cubes, in which players put together cubes, each with six different images, to make storylines. Second on the list is Qwirkle made by MindWare, a game in which players place similar tiles together to gain points. Those were followed by William Mark's Air Swimmer Remote Control Inflatable Flying Shark, a Zeppelin-like creation, which floats through the air as if swimming.

The top seller in Amazon's films and TV programmes department is the comedy-drama The Help, which is set in the 1960s civil rightsmovementera and follows the relationshipof a white woman and two black maids. The Tate Taylor-directed film was followed by the two final parts of the Harry Potter series, Harry Potter and the Deathly Hallows, Parts 1 and 2.

The online retailer's bestselling books are the sixth instalment of Jeff Kinney's Diary of a Wimpy Kid, entitled Cabin Fever, followed by Walter Isaacson's biography of Apple co-founder Steve Jobs, who died this year, and the Lego ideas book by Daniel Lipkowitz, which lists things to make with the ever-popular building blocks.