Shoppers have been urged to do their spending in high streets in the run-up to Christmas to stop traders going bust.
Non-essential stores in England reopen on Wednesday – and it could be make or break for many.
Experts say shops face a £9billion slump in pre-Christmas takings.
The British Independent Retailers Association said: “It’s the most important December ever for retailers.”
Stores forced to shut in the latest lockdown hope to claw back Christmas takings in just three weeks.
There is expected to be a stampede as non-essential shops in England are allowed to reopen on Wednesday.
Many traders say the survival of their business depends on the size of the spending frenzy.
People are being urged to support high streets amid fears shops face a £9billion slump in pre-Christmas takings.
Helen Dickinson, chief executive of the British Retail Consortium, said: “While reopening offers a lifeline for many shops, it will be the public who have the final say.
"Thankfully, Christmas is the perfect reason to shop, knowing that every purchase we make is a retailer helped and a job supported.”
She added: “Retailers have spent hundreds of millions to make shops Covid-secure...
“High streets, shopping centres and retail parks have all seen footfall nosedive during lockdown, with closed shops estimated to have lost around £2billion per week in lost sales.”
A flood of online ordering during lockdown means stores, especially smaller ones, face a huge battle to recoup losses.
The Centre for Retail Research is forecasting a £9bn year-on-year drop in retail sales in the six weeks to Christmas.
It predicts online takings will be up 58%, while sales in bricks and mortar stores are expected to be down 37%.
Andrew Goodacre, head of the British Independent Retailers Association, said: “This is the most important December ever for retailers and the high streets throughout the UK.
“We need customers to return to the shops and enjoy a traditional Christmas shopping experience and support the local community at the same time.
"It has never been more important to shop local.”
Gary Marsh, owner of gift and coffee shop Papilio at Heritage, in Thornbury, Glos, said reopening was “crucial”.
He added “we’d have been dead in the water” without December’s takings.
Hellen Stirling-Baker, owner of Sheffield toy shop Small Stuff, called the lifting of restrictions “incredible”.
The Mirror has championed town centres through our High Street Fightback campaign and Shop for Britain drive.
Fashion chain Primark aims to open 11 stores for 24 hours from Wednesday through to Thursday.
Others will stay open up to midnight until Christmas to help cope with demand.
The Covid crisis and changing shopping habits continue to claim high street victims.
The Centre for Retail Research calculated that by the start of November, at least 140,000 jobs in the industry had gone this year, with over 15,000 shops lost.
Shadow Business Secretary Ed Miliband said: “Businesses may be preparing to reopen but many are seriously struggling... after nearly eight months of difficult trading conditions, especially hospitality businesses which are facing fresh restrictions.
"Businesses are being badly let down and have a right to be very angry about how they’ve been treated.
“The Government must set out a strategic plan for the next six months to give businesses the support and certainty they need to survive the crisis, or risk jobs across the country being destroyed.”
Debbie McSweeney, of the Unite union, said: “We call on the Government to redouble its efforts to formulate a radical post-Covid blueprint to revive ailing town centres.
“Such a strategy is desperately needed as high streets underpin the social fabric of our communities.”