The first week of post-Christmas sales ended with an alarming drop-off in shopper numbers, according to retail research group SPSL.
Shopper numbers for 27 and 28 December were down 3% on 2004
Despite the rush for Boxing Day bargains which saw shopper numbers up 17% on last year, numbers for the week to 1 January slumped by nearly 8%.
The decline could simply mean shoppers just ran out of steam after the six-day trading week before Christmas.
But retailers will worry it could signify a tough trading year ahead.
However, SPSL's latest figures did confirm that a frenzied last week of shopping in the run-up to Christmas had averted the sales meltdown that many retailers had feared.
A 16% rise in shopper numbers compared with the same week the previous year meant that shopper numbers for the whole of December were only down by 0.1% on those reported in 2004.
In another encouraging sign, John Lewis said that sales at its flagship Oxford Street store were 12% higher in December 2005 than in December 2004.
The department store chain, which will publish detailed figures for all its stores on Friday, said the store had enjoyed its best Christmas in years.
"It was a spectacular Christmas for us," Noel Saunders, managing director of the store, told BBC News, adding that general economic conditions had improved for retailers in recent months.
"We saw a reduction in interest rates, falling fuel prices and much better weather for us during the early to mid autumn period."
Just a blip?
SPSL's research backs up the findings of other retail analysts, which have pointed to a fall-off in holiday sales after an initial rush.
Footfall reported a 12% fall in overall High Street traffic between Christmas and New Year despite stores reporting brisk business and frequent queues on Boxing Day.
"Is it just a blip brought about by inclement weather delaying shopping trips or is it a sign that consumers are hitting their shopping saturation levels, believing that the best bargains are gone?" said Dr Tim Denison, director of knowledge management at SPSL.
A more detailed picture of High Street health will emerge over the next few weeks as the UK's leading retailers release sales figures, starting with Next on Wednesday.