Seasonal shopping will not pick up until the last 10 to 14 days before Christmas, trade body the British Retail Consortium (BRC) has warned.
There have been moves to lure shoppers into London's West End
It came as some High Street chains have started to offer price discounts to try to overcome sluggish sales.
Some of the biggest reductions are at clothing stores, according to BRC director general Kevin Hawkins.
"I think this year there is a lot of discounting at the moment - more so than last year," he said.
"It has been led by the clothing retailers and department stores. The reason is that the autumn weather was so mild that it leaves them with the problem of getting rid of winter stock."
Many High Street retailers have launched a series of sales and special offers in a bid to lure stay-at-home consumers into early Christmas shopping.
The marketing push comes as the latest statistics show that retail sales are down on last year.
Christmas trading represents up to 60% of turnover for some stores, which fear that shoppers are waiting until the last minute in their hunt for bargains.
Argos, Currys, Debenhams and Borders are among the chains slashing prices.
Other retailers, including House of Fraser, Homebase, Focus, Tesco, Halfords and Superdrug, have introduced savings of up to 50%.
Mr Hawkins said online retailers were likely to perform well this Christmas.
There has been a rash of discount vouchers being distributed over the internet, as limited schemes are sent far and wide via e-mail.
As well as the much publicised Threshers voucher other online discount vouchers for stores which are circulating on the internet include ones for Selfridges, Urban Outfitters, Oasis, Dorothy Perkins, Gap and Warehouse.
Latest statistics from research group Footfall suggest that the number of shoppers visiting department stores is down 9% on the same time in 2005.
And a recent CBI report revealed a "disappointing" November for retailers. It showed 34% of retailers reported a decline in sales compared with last year, while 25% said sales were up.
Mr Hawkins said: "I think there will be plenty of incentives for consumers to come out and spend money.
"The issue is whether or not they come out, in what numbers and how near Christmas. My guess is it will be very much focused on the last two weeks to 10 days."
On Saturday an attempt was made to stimulate shopping in London's West End by making it entirely traffic free for the first time. Oxford Street and Regent Street were open to pedestrians only from 1030 GMT until 1700 GMT.
Organisers said the traffic-free event brought in an estimated one million shoppers, with some shop bosses reporting increased sales.
An estimated 40 million shoppers visit the West End during the six weeks leading up to Christmas, a quarter of whom are from overseas.
Despite the gloomy forecasts, some shop chains have reported increased sales on the same period last year, including John Lewis, up 16%, Boodles, up 30%, and Selfridges, up 11%.