People returning to the UK from Croatia may soon face a 14-day isolation on their arrival after the country passed the Government's quarantine benchmark.
The Balkan nation's cases have now passed the threshold of 20 infections per 100,000 people in a seven-day period, at 21.5.
Croatia recorded 162 new infections on Sunday alone. It has seen 6,571 Covid-19 cases and 166 deaths so far.
The news leaves around 20,000 British tourists potentially scrambling to get home as fears grow the country could be next to be added to the UK's quarantine list.
Other countries such as Denmark and Switzerland are also close to reaching the Government's quarantine benchmark.
Travel expert Paul Charles, of the PC Agency, tweeted that Croatia was "not looking too healthy'" and shared data that suggested Croatia was behind Spain and France in terms of new cases over a seven-day period.
"Many people have been asking where they can go for a late summer holiday" he tweeted.
"Having crunched the data, I’d recommend Italy and Turkey before the end of August.
"Greece will not be added to the quarantine list this week but Croatia is not looking too healthy."
It comes after Transport Secretary Grant Shapps announced late on Thursday that anyone arriving from France after 4am on Saturday is required to quarantine for 14 days due to rising coronavirus cases in the country.
The move sparked a rush on return tickets, which saw many people spending hundreds of pounds to make it back in time.
Eurotunnel Le Shuttle, the train service which carries vehicles through the Channel Tunnel, booked out shortly after the announcement.
A spokesman said 12,000 people tried to book tickets in the hour after the new rules were announced at around 10pm on Thursday, compared with just hundreds normally.
Some air fares were more than six times more expensive than normal.
The quarantine conditions also apply to travellers returning to or visiting the UK from the Netherlands, Monaco, Malta, Turks & Caicos and Aruba.
