UK detects third case of Omicron variant 

A third case of the new Omicron variant has been detected in the UK

Shoppers wearing face masks in Regent Street, London.

A third case of the Omicron variant of coronavirus has been detected in the UK

Mandatory mask-wearing will return to shops and public transport on Tuesday, UK Health Secretary Sajid Javid said as a third case of the variant was detected.

He told families they should plan for Christmas "as normal" and said it is "nowhere near" time to reintroduce social distancing rules and work-from-home guidance, despite a raft of precautionary measures being reintroduced to tackle the concerning strain.

But later on Sunday, the UK Health Security Agency (UKHSA) said it had identified another case of Omicron in an individual with links to travel in southern Africa who visited Westminster in London before leaving the country.

Dr Jenny Harries, the UKHSA chief executive, acknowledged it is "very likely" that further cases of Omicron, which is feared to spread rapidly and may evade existing vaccines to a degree, will be discovered in the coming days.

Targeted testing is being carried out in locations where the latest positive case visited while likely to be infectious, as well as in Nottingham and Brentwood, Essex, where the first two cases of Omicron were identified.

The detection of the strain classified as a “variant of concern” by scientists came ahead of the new testing regime being introduced under measures to slow its spread.

International arrivals entering the UK from Tuesday morning will have to take a PCR test for Covid-19 and self-isolate until they get a negative result.