Today is set to be the biggest shopping day of the year as 15 million shoppers hit the shops to spend a forecast £3.6bn.

With just two shopping days left until Christmas, as much as £2.6m each minute could be spent today as 15 million shoppers hit the high street, according to retail analysts.

The dash to spend cash is expected to be even bigger today after poor weather on Saturday meant many consumers cancelled shopping trips.

Visa expects to process 31 million transactions in the U,K which are set to peak between 1pm and 2pm. Consumers are expected to spend an average of £15,000 on their Visa cards per second.

A last-minute dash would come after a subdued Christmas trading period so far for some retailers. In London’s West End, for instance, footfall rose 3.6% week-on-week last week to December 22, but was down 9% year-on-year, the New West End Company reported.

Morrisons predicts that 11:44 am today will be the busiest minute of the year, as a total of 45 trolleys per second are expected to run through checkouts across its stores. Today is also expected to be the busiest day for selling food.

Morrisons retail director Martyn Fletcher said: “People want the freshest ingredients by Christmas Eve and that’s why our stores are busiest on 23rd December. This year we are ready with extra staff, computerised queue management and an army of bag packers to make sure shoppers get the quickest and most stress-free experience possible.”

Morrisons has extended openings hours to 11pm in 230 stores, with some opening at 7am. More than 100 head office staff are pitching in and leaving their desks to work on the shop floor. And the grocer will be using an Intelligent Queue Management system, which analyses the number of customers coming into the store to predict how many checkouts will need to be open when those customers have completed their shopping.

Professor Joshua Bamfield, director of the Centre for Retail Research, said: “We expected Saturday to be the major panic shopping day of the year but because of the bad weather in some places I am sure a lot of people will head out shopping on Monday instead.”

The rush on Monday will also be fed by the many people whose festive breaks started last Friday.

A British Retail Consortium spokesman added: “With Christmas falling midweek and with lots of people having taken Monday and Tuesday off work it certainly means Monday and Tuesday may well be busier than we would normally see in the weekdays.”

Customers are also expected to bag a bargain on Christmas Day itself. The Centre for Retail Research predicts spending will hit £228m online through some six million transactions.

eBay research in partnership with retail analyst Conlumino showed that in the run up to Christmas consumers will spend £2.02bn through tablet devices and over £500m will be spent shopping in bed.