At a Downing Street press conference last night, Boris Johnson said people must work from home where possible from Monday. From tomorrow, face masks will be a legal requirement in most public indoor areas such as theatres and cinemas, with exemptions for eating and drinking in hospitality venues.

People will need a vaccine passport – available to the double-jabbed on the NHS app – to attend large events and nightclubs from next week.

Health secretary Sajid David was heckled in the Commons as he announced the shift to ‘Plan B’ as anger over the series of Christmas parties held by MPs last December, while the UK was in lockdown, intensified.

Matthew Fell, CBI chief policy director, said: “Fresh restrictions are a big setback for businesses, particularly for those in hospitality and retail who are in a critical trading period, as well as others such as transport. While Covid certification can support public health, careful implementation and enforcement will be required to assist businesses affected.

“It will be vital that the impact of these restrictions is closely monitored, and that the government is ready with targeted support as required.”

Transport and travel union TSSA called on the government to reintroduce the furlough scheme.

Manuel Cortes, TSSA general secretary, said: “Throughout the pandemic this government has failed to act quickly enough or take the measures needed to prevent the spread of this deadly virus, save lives and protect the economy.

“Our members in the travel industry are already suffering as a result of the reintroduction of travel restrictions and now many more workers are going to feel the pinch as Plan B kicks in. The government must bring back the furlough job retention scheme to ensure no one loses their jobs as result of the new restrictions.”

Small businesses around the UK expressed concerns that the new rules could have a detrimental effect on their income.

Jo Ferreday, founder of hospitality and events company Sheer Edge, said: “The majority of my income is based on live and in-person events so the move to Plan B has been a real blow, especially as there was no indication about how long these new restrictions will be in place. 2022 has a huge shadow of uncertainty over it.”

Paul Asbridge, founder of music entertainment company Jam Hot, said: “Let’s hope we’re the entertainment that Boris books to perform at the No.10 Christmas party this year, because all of the other events in our diary are dropping like flies.”