In an effort to stem the tide of more virulent variants of the coronavirus, the French authorities have announced a reinforcement of already strict rules for those wishing to enter the country.
The coronavirus variants from Britain and South Africa, both recognised as far more contagious than the original cause of Covid-19, have been blamed for the sudden upsurge in the number of infections in Ireland, Danmark and the United Kingdom.
There is a danger that these variant forms will displace the original virus, just as the vaccination campaign builds up speed across Europe.
Britain bars travel from South Africa after new Covid-19 variant detected
For these reasons, French Prime Minister Jean Castex has announced that, from Monday, travelers arriving from anywhere outside the European Union (and this now includes post-Brexit Great Britain) must produce proof of a recent negative Covid test before they will be allowed into France.
Follow-up test obligatory
All non-EU arrivals will also have to accept one week of self-isolation and undergo a follow-up test at the end of that period.
Up to now, only those arriving from countries considered as high-risk were obliged to provide certificates and observe a period of quarantine.
Ireland and Denmark are special cases.
How Ireland became 'most infectious' coronavirus country
Although both are EU member states, their high levels of infection and exposure to the more virulent form of the coronavirus, will require the imposition of extra regulations. A coordination framework to cover these internal exceptions is to be established at the next European Council meeting, scheduled for 21 January.