Food charities and restaurants are warning of a mountain of wasted festive meals, as hospitality businesses struggle with last-minute cancelled bookings amid soaring Covid-19 cases.

Thousands of restaurants, cafes, pubs and hotels had placed large orders for turkeys, Christmas puddings and other festive food in what should have been one of the busiest weeks of the year.

But venues have been knocked by a dramatic drop-off in custom in recent days, as growing concerns of the spread of the Omicron variant have caused customers to scrap their festive plans. While hospitality has been allowed to remain open by the government, scientists including England’s chief medical officer, Chris Whitty, have advised against socialising, leading to urgent calls for government support for the struggling industry.

FareShare, the UK’s largest food redistribution charity, said offers of food – including turkey, seasonal produce, chocolate and coffee – had increased by 5% over the past seven days, but that it would struggle to take all it had been offered.

Lindsay Boswell, FareShare’s chief executive, said: “In just the past week, FareShare has seen an increase in the number of offers of food to us from businesses in the hospitality sector, as a result of the cancellations of table bookings.”

The organisation takes good-quality surplus food directly from suppliers and supermarkets and redistributes it to almost 11,000 frontline charities and community groups across the UK, typically providing meals to vulnerable people.

Boswell said supply chain disruption and lack of availability of chilled vans suitable for transporting fresh produce was hampering its efforts to collect all the food offered, but said it would endeavour to “accept offers of large volumes of surplus raw ingredients wherever possible”.

On Friday, Nicola Sturgeon announced that the Scottish government was putting £100m into the food and drink supply chain, to support hospitality businesses, wholesalers and other sectors including the wedding industry. The Scottish first minister once again called on the UK government to provide support to businesses.

Boswell said: “In Scotland, a government plan is under way to support the wholesale industry to ensure surplus stock, where possible, is redistributed by FareShare to those that can make good use of it.”

The chef and restaurant owner Simon Wood, who runs restaurants in Manchester and Cheltenham, has seen his bookings fall by a third over the past week. Wood had been expecting Friday to be the busiest of the year in his Manchester fine dining restaurant, but said cancellations meant he would only serve 11 customers.

“It is frightening,” said the former MasterChef winner. “I am now sitting here thinking do I get it [next week’s food order], what do I do? There is no way of knowing what is going to happen.”

Wood said he had not yet been left with any surplus food “as I have been very careful with what I have ordered”. Yet he was fearful that the coming week would bring more cancellations.

“It is scandalous. We depend on December in this industry, it’s what gets us through to March.”

Rishi Sunak, who jetted back to the UK from California on Friday, is under intense pressure to prop up struggling businesses for which trade has evaporated.

In a sign of the impact of cancelled bookings throughout the food and drink supply chain, wholesaler Brakes Foodservice said it had received fewer orders over the past week than anticipated for this time of year.

A spokesperson for the company urged consumers to give as much warning as possible to restaurants if they had to cancel their booking, to help the company plan more effectively and help minimise waste, but said much fresh produce consumed in winter had already been brought to the UK from abroad.

Brakes said: “Any sudden closures or restrictions inevitably cause huge supply chain issues and potential waste. While frozen and dry foods can be stored or redistributed, in the case of fresh meat, fish, fruit and veg, waste is impossible to avoid.”

The company said it was monitoring the situation closely and would work with FareShare and other food charities if necessary.