Quarantine-free travel into the UK has been suspended as all travel corridors have now closed.
Anyone who arrives in the UK from every destination will need to self-isolate for 10 days or receive a negative result from a coronavirus test taken at least five days after they enter the UK.
Passengers flying in from overseas will now also have to show proof of a negative Covid test before setting off – as part of rules which had been due to come into force last week.
It comes after the government banned flights from South America, Portugal and Cape Verde due to the emergence of a new variant in Brazil.
A number of exemptions to the travel corridor policy – such as business travel – will be also suspended.
The rules – which will be a further blow to the travel sector – came into effect from 4am on Monday.
Labour accused the Government of “closing the door after the horse has bolted”, saying the announcement was too late to have stopped the arrival of “worrying” strains.
Two variants of interest have been identified in Brazil – though only one, which has a small number of mutations, has been detected in the UK.
Listen to our coronavirus podcast