All travel corridors will close from Monday, meaning everyone arriving in the UK
will have to self-isolate.
The tighter border restrictions announced by Boris Johnson are aimed at protecting the progress made with the rollout of vaccines in the face of new coronavirus variants being found around the world.
It had already been announced everyone travelling to the UK from Monday will need to have proof of a negative COVID-19 test.
Under the travel crackdown, ending the quarantine exemption for arrivals from certain countries, people will also have to immediately self-isolate on arrival for 10 days, unless they have a negative test after five days.
This will be backed by more spot checks to ensure people are remaining in self-isolation.
The new regime will be in place until at least 15 February while further work takes place on how to manage the threat posed by mutations of the virus.
The government has also said it will continue to impose flight bans from countries where new strains are formally identified.
The prime minister told the Downing Street news briefing: “It’s precisely because we have the hope of that vaccine and the risk of new strains coming from overseas that we must take additional steps now to stop those strains from entering the country.
“Yesterday we announced that we’re banning flights from South America and Portugal and to protect us against the risk from as-yet-unidentified strains we will also temporarily close all travel corridors from 4am on Monday.
“Following conversations with the devolved administrations we will act together so this applies across the whole of the UK.”