The Scotland-wide lockdown from Boxing Day will see shops miss out on an estimated £135 million for each week they are closed, the Scottish Retail Consortium has said.
Nicola Sturgeon announced all of mainland Scotland will be put under Level 4 coronavirus restrictions on December 26 for at least three weeks.
Non-essential shops, restaurants and pubs will have to close while the restrictions are in place, although takeaway food will be permitted.
The First Minister also announced a travel ban over the festive period between Scotland and the rest of the UK – and indoor gatherings will only be allowed on Christmas Day for up to eight people from three households.
The SRC has estimated that the shutdown could see shops miss out on £135 million in lost revenue each week during the traditionally-busy shopping period after Christmas.
David Lonsdale, the SRC director, called for additional financial support for shops and an extension of business rates relief into 2021-22.
Mr Lonsdale said: “We recognise that Government has difficult decisions to make and the situation with the pandemic is fast moving, but this hugely disappointing news rounds off a torrid year for Scottish retail and is a further hammer-blow to non-food stores who have already borne so much during this crisis.
“Retailers in Scotland have invested over £40 million thus far making stores Covid-secure for customers and staff, and Sage’s advice has said throughout that closing non-essential retail has a minimal impact on the spread of the virus.
“The consequences of this move could be severe. This decision comes only a week after the end of the local lockdowns in west central Scotland and slap bang in the middle of peak trading which so many are depending on to power their recovery and tide them over the leaner winter period.
“Faced with this news – and the prospect of losing £135 million each week in revenues during the lockdown – many stores will be in serious difficulty.
“Many could be lumbered with unsold pre-Christmas stock which will be difficult to shift in the absence of the usual Boxing Day and new year discounted sales events, adding to cash flow woes.
“All of this will have implications for the survival of shops, for retail jobs and the vitality of our retail destinations.”