Of the 105 cases, 11 of them identified over the last five or six days do not appear to have links to international travel, which suggests there may be pockets of spread in local communities.

Mobile testing units and home testing kits will be deployed to areas where the COVID-19 variant has been.

Matt Hancock told a Downing Street press conference: "It's a big effort getting this new variant... essentially finding every single case of it, that is the goal."

The health secretary said the the door-to-door testing regime, along with enhanced contact tracing efforts, was an attempt to "come down on it hard".

It was "absolutely vital" that people minimise all social contact in the areas where South African cases had been identified, he added.

And now there is another variant even the scientists are saying they are worried

I've been trying to work out why there are so many British travellers in Dubai. I mean there's simply no justification for so much continued travel. People keep finding excuses : https://www.arabnews.com/node/1800561/middle-east

The UK has never banned international travel altogether - as other countries have done. New hotel quarantine rules have not yet come into force and other border measures have only been introduced recently.

The government hasn't issued any specific guidance on what constitutes "essential travel", and says only that "reasonable excuses" to leave home - such as work - also apply to international travel.

There is also concern about the level of compliance with the existing rules on international travel - with up to a third of travellers potentially disobeying rules to self-isolate at home.

To combat this, a new hotel quarantine policy for England was announced by Boris Johnson on 27 January. A week after the announcement, the policy has still not been implemented.

The government's failure to have proper quarantine measures in place in March as the infection was spreading fast was a grave error and meant Covid spread faster and reached more people.

A recent study found the virus was introduced to the UK "well over a thousand times in early 2020", with a third of transmission chains brought in from Spain, followed by 29% from France, neither of which faced any restrictions. China accounted for just 0.4% of imported cases.