Retailers have reported an "intensive" level of shopping amid hopes of a cut-price Boxing Day bonanza for shoppers across Britain.

High streets and malls across the country are offering heavy discounts to make up for the dent to sales caused by plummeting pre-Christmas temperatures and heavy snow.

Consumers are also expected to snap up bargains before the VAT increase from 17.5% to 20% on January 4.

The fact that Boxing Day falls on a Sunday means trading hours are restricted to six hours.

By 1pm on Sunday, 70,000 shoppers had swarmed over the 200 shops at the Trafford Centre on the outskirts of Manchester. Because of the Sunday trading laws, larger shops were squeezing in trade from 11am to 5pm, with an "intensive" level of shopping.

Gordon McKinnon, director of operations at the centre, said the sales had "gone off like a rocket".

A spokesman for Bluewater shopping centre in Greenhithe, Kent, said more than 100,000 visitors were expected to pass through its doors - with more than 900,000 people expected to browse the sales between now and January 1.

General manager Andrew Parkinson said: "Our car parks were at 70% capacity by 12pm as guests arrived early to have breakfast before spending the day at Bluewater. Key to this is that most retailers did not go on sale pre-Christmas. Shoppers are therefore travelling to Bluewater to find real bargains, of which there are plenty."

At Braehead shopping centre near Glasgow, eager clothes shoppers queued outside Next and New Look ahead of the stores' 7am opening. General manager Peter Beagley said that numbers were up on the previous year, adding: "People were driving into our car parks as early as 5am aiming to be first to catch the best of the sale items. I've no doubt that shoppers also had their eye on the VAT increase in January and were buying items to save on paying the extra VAT."

The Arndale Centre in Manchester reported "phenomenal" trading, with 150,000 through the doors and were on track to get another 20,000 shoppers in by close of trading. "It is difficult to get into some of the shops because of the sheer volume of people," said Glen Barkworth, general manager of the Arndale.