Meanwhile, trade groups have also warned that the reintroduction of further virus curbs could have a "devastating" effect on businesses across the country.
British Prime Minister Boris Johnson late on Wednesday afternoon announced measures to contain the spread of the Omicron variant.
From Monday, December 13, everyone who can work from home has been advised to do so. Mr Johnson has given employers the rest of this week to discuss the new measures with staff.
From Friday, December 10, face masks have been reintroduced to most indoor venues, including theatres and cinemas.
Mr Johnson said the mask guidance would include exemptions for when eating, drinking, exercising or singing.
He said the NHS Covid pass is to be mandatory in England in a week’s time for nightclubs and venues where large crowds gather.
The Covid health certificate will apply to unseated indoor venues with more than 500 attending, and outside where there are more than 4,000 people.
The uncertainty around implementation of the measures affected London traders, leading to a heavy sell-off in the pound.
The pound moved 0.28 per cent lower compared with the US dollar at 1.319, and decreased 0.94 per cent against the euro at 1.165.
Meanwhile, the UK's FTSE100 stayed marginally higher despite a slide in value among many travel and leisure stocks.
Travel operators Jet2, National Express and EasyJet all also moved lower.
Meanwhile, Wagamama owner The Restaurant Group moved 2.6 per cent lower and Cineworld slipped by 4.1 per cent.
The Night Time Industries Association said leisure companies should "not be thrown under the bus" with restrictions as it recovers.
"The pre-Christmas period is absolutely crucial for our sector and reports today that Plan B, including vaccine passports, will have a devastating impact on a sector already so bruised by the pandemic," said Michael Kill, the trade group's chief executive.
"The government's own report on the subject concluded that vaccine passports wouldn't even have a significant impact on virus transmission.
"You do, therefore, have to question the timing and rationale for this announcement. Is this sound, evidence-based public policy making, or is this an attempt to move the news agenda on from a damaging story about the Downing Street Christmas party?
"Nightclubs and bars must not be thrown under the bus for the prime minister to save his own skin."