Several countries are likely to be removed from the Government’s quarantine exemption list on Thursday, figures suggest.
Denmark is currently recording a seven-day rate of 65.2 coronavirus cases per 100,000 people.
This is up from 33.8 a week ago.
A rate of 20 is the threshold above which officials consider triggering quarantine conditions.
Iceland and Slovakia are also at risk of having quarantine measures introduced, with rates of 80.4 and 25.9 respectively.
Other countries above or near the threshold include Greece (20.9) and Italy (18.4).
The rates in the UK and Ireland are 47.3 and 38.3 respectively.
Figures have been calculated by the PA news agency based on data collected by the European Centre for Disease Prevention and Control.
Changes to the Government’s list of countries from which arrivals in England do not need to self-isolate for 14 days are usually announced on Thursday at 5pm and implemented the following Saturday at 4am.
The devolved nations have their own exemption lists which are similar but not identical to that created by the UK Government.
The travel industry has been badly hit by quarantine restrictions.
It has called on the Government to allow coronavirus testing at airports to reduce self-isolation periods for those who get a negative result.