Italy and Greece are at risk of being added to the Government's travel quarantine 'red list' this evening after both suffered a spike in coronavirus cases.
Greece has recorded 20.5 cases per 100,000 people in recent days while Italy has recorded slightly above 20 per 100,000.
The Government currently uses a threshold of 20 cases per 100,000, along with a number of other criteria, when it makes decisions on whether to add or remove countries from its quarantine list.
Transport Secretary Grant Shapps is due to unveil the latest changes to the rules this evening.
However, even if travel to Greece and Italy is restricted it is thought the Government could still allow travel to some Greek and Italian islands which have lower infection rates than the mainland.
Meanwhile, Sweden and Poland are also in danger of being added to the 'red list' after they recorded infection rates of 30 per 100,000 and 24 per 100,000 respectively.
Transport Secretary Grant Shapps will set out the latest updates to the Government's travel quarantine 'red list' this evening
Italy has just creeped above the UK's threshold for imposing travel restrictions of more than 20 cases per 100,000 people. Rome is pictured on September 30
The list of countries which UK travellers can visit without facing 14 days in self-isolation continues to dwindle.
The list of places Britons can travel to and return from without quarantining or taking Covid tests was reduced to just nine last week.
Denmark, Iceland, Slovakia and the Caribbean island of Curacao were all removed from the safe list last Thursday.
There are still more than 60 countries on the UK's 'green list' where quarantine is not required on return, but many have their own restrictions on arrival or are closed to visitors completely.
Downing Street remains under intense pressure to change the UK's travel quarantine rules amid growing fears for the future of the aviation and travel industries.
Ministers have faced calls for months to replace the current 14 day self-isolation restrictions for people returning to the UK from high risk countries with a more nuanced system of airport testing.
Advocates believe testing on arrival could open the door to significantly reducing the two week quarantine period to potentially less than seven days.
A double testing approach would see travellers tested on arrival and then told to self-isolate for something like five days when they would then be tested for a second time.
Two negative tests would be enough to allow people to end their period in quarantine and return to normal life.
However, ministers have been reluctant to approve airport testing because of concerns that the approach could fail to identify some people who have the virus.
This is because of the amount of time it can take for the virus to be detectable after the moment of infection.