Shoppers stroll through Carnaby Street in London on Tuesday. AP

Finance Minister Rishi Sunak said some 200,000 firms would be eligible for one-off grants to offset losses from what is normally the busiest time of year.

Under the support announced on Tuesday, hospitality and leisure firms in England will be eligible for grants of up to £6,000 for each of their premises, accounting for almost £700 million of the new package.

Pubs and restaurants have seen Christmas parties and bookings cancelled because of the spread of the Omicron variant of the virus, hitting December trade by as much as 60 per cent.

Sunak said the government recognised that businesses in the hospitality and leisure sectors were facing "huge uncertainty at a crucial time."

Shoppers carry shopping bags as they walk along Oxford Street in London. AFP

The government is banking on an ambitious campaign to get all adults in England to have a booster jab of a COVID-19 vaccine by the end of December to try to stop the spread of the mutation.

The director of the Wellcome charitable foundation, Jeremy Farrar, told BBC radio transmission was "eye-wateringly high", as daily infection rates nudged towards 100,000.

But unlike governments in some of Britain's nearest neighbours on the European mainland, Prime Minister Boris Johnson has ruled out immediate curbs in the run-up to Christmas. Tighter public health measures could yet be introduced after this weekend, according to media reports.

Staff absences

Across the country, all sectors of British industry have been hit as staff contract the virus and are forced to self-isolate at home.

As the Christmas getaway begins, train companies apologised for employee absences and warned they could affect scheduled services and even lead to cancellations.

Edinburgh Castle and the National History Museum in London — two of the country's most visited attractions —were forced to close their doors because of staff illnesses.

A member of the public carries shopping purchases in Primark bags as they walk along Oxford Street. AFP

That came after several theatres in London's West End entertainment district cancelled performances to protect performers and the public.

Meanwhile, the hotel and restaurant industry has seen closures because of a lack of staff.

And in the public sector, the government has called for retired teachers to help out, as the virus forces staff out of the classroom.

In London, unions have warned that firefighters face "unprecedented" manpower shortages, although its response to emergencies has not yet been affected.

Johnson has come under pressure from business owners and industry bodies to reintroduce support packages for Covid-hit sectors, who were already struggling after curbs in the last year.

He is, however, facing intense pressure from within his own ruling Conservative party not to bring in tougher restrictions on public freedoms.