Retailers are calling on the government to step up financial support for businesses in the south and east of England which have been forced to close in the last days before Christmas.

The prime minister announced on Saturday afternoon that non-essential shops and services, including clothing, toyshops, electrical goods outlets and hairdressers, would have to close from midnight under new tier 4 restrictions. As a consequence thousands of outlets in the south including London, Kent, Hertfordshire, Berkshire and Surrey will be left with piles of unsold stock.

After a grim year for the high street, many retailers were relying on a last-minute rush to stores at what is normally the busiest trading period of the year. With the deadline now past for when most online retailers can deliver to homes before Christmas Day, shoppers usually turn their attention to the high street and shopping centres.

London Chamber of Commerce and Industry (LCCI) called on the government to announce “exceptional and immediate cash grant aid” for all retail, leisure and hospitality businesses forced to close their doors under the tier 4 restrictions.

Richard Burge, the chief executive of LCCI, added that the chancellor “must also issue appropriate instructions to banks and landlords, and must suspend the payment of all forms of taxes and rates to national and local government bodies”.

Andrew Goodacre, the chief executive of the British Independent Retailers Association (Bira), which represents thousands of independent shops, said the closures in the south and south-east were “a disaster for those businesses”.

“They have only been open for 17 days in the busiest month of the year and will now miss out on the festive period and new year sales,” Goodacre said.

“They need financial support that reflects what they have lost and certainly better than the grants made available in November (many of which have not been paid).”

Large retailers, such as John Lewis, said customers would be able to pick up goods ordered online at stores, helping to keep business flowing. But many small shops are unable to offer this facility.