The high street is set to experience its busiest day of the year as shoppers stock up on last-minute Christmas gifts and provisions.
Queues of up to two hours were reported at Marks & Spencer's food collection service in some stores, after a BBC Good Food poll suggested almost a third of consumers (31%) plan to do their main Christmas food shop today.
Disgruntled M&S customers took to social media to complain of long delays affecting the collection service at branches across the country.
Shoppers posted pictures of lengthy queues both inside and outside stores, with some reporting waits of more than two hours to collect their pre-ordered goods.
Customer Scott Rose (@lordpercy) tweeted: "2 hours to pick up a turkey at #cheshunt won't be back next year #M&S."
At 9.40am Nicola Cramond (@nic_cramond) said: "Preordered my food as I do every year for the past 10 year. Pick up 8.30am-9am Irvine, I'm still in the queue to pay! #neveragain."
James Cameron (@JamesCambo76) said: "Your collection scheme is a joke. Why offer a service you cannot deliver?? M&S Newport, 40 mins = 40 steps!!"
In Beckenham, London, images showed queues for the service winding outside, almost reaching the car park.
At the supermarket's Handforth Dean store in Cheshire, staff handed out mince pies to unhappy customers as they endured the wait.
Waitrose predicted the hour from 11am would be its busiest period, with sales expected to be 3.5 times higher than on a typical Wednesday, while the busiest branch is expected to be Oakgrove in Milton Keynes.
Sainsbury's expected its checkouts to hit their peak between 11am and 1pm and Tesco has taken on extra staff to prepare for what it predicts will be its busiest in-store shopping day.
Bluewater Shopping Centre in Kent said it was "Christmas shopping as usual" two days after shoppers were left stranded for up to six hours after heavy traffic blocked car park exits.
Police were called to help clear the backlog on Monday when a broken down vehicle and high visitor numbers caused traffic chaos.
A spokeswoman today said: "Traffic is flowing freely and it's Christmas shopping as usual."
Visa Europe predicts that high street spending on its cards will reach £1.3 billion, peaking between 1pm and 2pm when 3.2 million transactions will take place, making it the biggest shopping day of the year.
Shoppers are expected to make more than 37 million transactions, up 10% on last year, while the overall amount spent is predicted to be 3% higher.
Kevin Jenkins, Visa Europe managing director for UK and Ireland, said: ''On December 23, Brits will race to the high street to pick up last-minute presents, despite starting their Christmas shopping early this year with record amounts spent online on Black Friday.
''In keeping with previous years, the busiest day for Christmas shopping this year will be two days before Christmas where we are likely to see £1.3 billion spent on the high street.''
''More than £1 million will be spent on Visa cards every minute, rising to nearer £2 million every minute during the lunch time rush between 1pm and 2pm.
''Shoppers will demand quick and easy purchases during this busy period, and retailers with a contactless offering are likely to be the winners as they could see shorter queuing times and happier customers.''
An M&S spokeswoman said: "Today is one of the busiest food shopping days of the year and we manage collections with allocated timeslots. Our teams are working hard to ensure any waiting customers are looked after and can collect their order as quickly as possible."