Passengers arriving in the UK from Croatia, Austria and Trinidad and Tobago will now have to quarantine for 14 days, while Portugal has been added to the travel corridor list.

Here are the key dates in the UK’s 14-day quarantine policy:

– June 8

Two-week quarantine rules for all UK arrivals come into force in efforts to guard against a second wave of coronavirus.

All passengers – bar a handful of exemptions – are required to give contact details and the address where they will isolate.

– July 3

The Government announces that quarantine restrictions for people returning to or visiting England from destinations such as Spain, France, Italy, Greece and Germany will be lifted from July 10.

The US is excluded from the list of 73 countries and territories, published by the Government, where English holidaymakers can visit without self-isolating on their return.

The Welsh Government and the Northern Ireland Executive decide on the same approach, while the Scottish Government produces a list of just 39 countries.

– July 10

Serbia is removed from England’s quarantine-free list on the day the “air bridges” policy is implemented.

The Government says that the Joint Biosecurity Centre and Public Health England have “updated their coronavirus assessments of Serbia based on the latest data”.

– July 24

A further five countries are added to the list of England’s so-called travel corridors, with anyone coming from Estonia, Latvia, Slovakia, Slovenia and St Vincent no longer required to isolate for two weeks on arrival.

Popular holiday destinations including Portugal, Thailand and the US remain notable absentees from the list.

– July 25

Holidaymakers returning from Spain are told they must quarantine for 14 days after ministers removed the country from the UK’s safe list.

All four administrations – England, Wales, Scotland and Northern Ireland – opted to join forces over the move, which comes into effect from midnight.

– July 30

Luxembourg is removed from the travel exemptions list, the Government announces, with all passengers travelling to the UK from the country required to quarantine for two weeks.

– August 6

Travellers arriving in the UK from Belgium, Andorra and The Bahamas are told to quarantine for 14 days from August 8, after the three countries are removed from the list of travel corridors.

– August 11

Travellers arriving in the UK from Malaysia or Brunei are no longer required to self-isolate for 14 days after being added to the Government’s exemptions list.

– August 20

Croatia, Austria and Trinidad and Tobago are all removed from the list of exemptions, with those travelling to the UK from these countries required to quarantine for two weeks.

Transport Secretary Grant Shapps says the measures come into effect from 4am on Saturday.

Meanwhile, passengers arriving in the UK from Portugal no longer have to self-isolate after it was added to the travel corridor list.

In Scotland, travellers from Switzerland will also be required to quarantine for a fortnight – the only nation of the UK to add the country to its quarantine list.