Work-from-home guidance will return, Covid health certificates will become mandatory in large venues and mask rules will be extended to combat the Omicron variant as Boris Johnson announced a move to his Plan B to tackle coronavirus.

The Prime Minister warned it is clear the new strain is “growing much faster” than Delta and cases of Omicron could be doubling every two or three days as he strengthened England’s rules to slow the spread of Covid-19.

Mr Johnson said that guidance to work from home where possible will return from Monday, and mandatory mask wearing will be extended to public places like cinemas and theatres from Friday.

(PA Graphics)(PA Graphics)

The NHS Covid pass will be mandatory in nightclubs and other venues where large crowds gather from “a week’s time”, the Prime Minister told a hastily-arranged Downing Street press conference, as he described the measures as “proportionate and responsible”.

But Mr Johnson faced questions over how the public can accept his rules amid anger over allegations Downing Street staff broke Covid rules in a Christmas party last year.

Simultaneously in the Commons, Health Secretary Sajid Javid warned there are 568 cases of Omicron confirmed but that the true figure is estimated to be “probably closer to 10,000”.

But he also faced heckles of resign as he updated MPs on the new restrictions, which he said would be reviewed on January 5.

Mr Johnson said the mask guidance would include exemptions for when eating, drinking, exercising or singing.

The Covid health certificate will apply to unseated indoor venues with more than 500 attendees, and outside where there are more than 4,000 people.

The Prime Minister added that the pass can be obtained with a negative lateral flow test or by having had two doses of a vaccine but hinted this could change by saying “we will keep this under review as the boosters roll out”.