British shoppers will spend £2.3 million a minute this Black Friday - a 19 per cent increase on last year - despite warnings that they should "ignore the hype" and exercise caution.

Some 14 million British consumers are expected to participate in the global shopping event, now the biggest shopping day in the UK, and will spend a predicted total of £1.96 billion, according to VoucherCodes.co.uk and the Centre for Retail Research.

Read more: UK Government should scrap Toblerone changes says MSP

On Friday November 25 itself, 37 per cent of shoppers are expected to hunt for bargains online while 63 per cent will hit the high street and malls for computer games, clothes, gadgets and alcohol.

Online spending on Black Friday is expected to reach £1 billion, up 16 per cent on last year, while it is anticipated that the majority who opt for the High Street will spend a lower total of around £961 million.

Well over half of online sales, 59 per cent, are set to be made via a mobile device, accounting for £591 million of the total spending.

Claire Davenport, managing director at VoucherCodes.co.uk, said: "This year, whilst growth in spending is supposed to be slightly more modest compared to previous years - our research predicts a 19 per cent year-on-year increase in spending for Black Friday - the date will be a key one for shoppers and retailers alike."

Meanwhile, separate figures from IMRG predict that shoppers will spend £1.27 billion on Black Friday, up 16 per cent on last year.

Read more: UK Government should scrap Toblerone changes says MSP

However the predictions come as watchdog Which? warned shoppers to "do your research" after finding that half of last year's deals were cheaper in the months before and after Black Friday.

A poll by research consultancy Future Thinking suggests that half of shoppers believe Black Friday is a "marketing gimmick" and just 19% believe that it offers the best deals.

Future Thinking spokeswoman Adele Gritten said: "While Black Friday may be neatly situated between the November paycheck and the Christmas shopping season, consumers are questioning whether the shopping tradition really offers them a good deal.

"When retailers are offering deals throughout the year and online discounts are dime-a-dozen, it's no surprise that consumers are taking time to properly scrutinise the Black Friday deals.

"While bargain-hungry shoppers will pack the most popular stores, the more sceptical consumers will prefer to stay at home, check the prices on their phones and won't be fooled by the marketing."

Read more: UK Government should scrap Toblerone changes says MSP

Sarah Pennells, founder of the money website SavvyWoman, also urged consumers to do their research before Black Friday, warning that some shops use the event to offload old or unpopular stock.

She suggested people "ignore the hype" and make use of price tracker sites such as Idealo and camelcamelcamel to make sure a bargain is genuine.

Ms Pennells said: "Take a step back from the 'buy now' frenzy. Shops use a lot of clever psychological tricks on Black Friday and one of them is to get us to buy in a hurry. It's one of the oldest sales tricks in the book."