British holidaymakers scurried to get home on Friday after the government said it will reimpose a 14-day quarantine for travellers from France and the Netherlands, prompting Paris to quickly announce a "reciprocal measure".
The new policy was announced late Thursday to come into effect at 4am (0300 GMT) on Saturday -- sparking a dash for the coast by many of the estimated 160,000 British holidaymakers currently in France.
Eurotunnel, which operates a drive-on train service for cars through the Channel Tunnel, warned travellers not to turn up without a reservation at its terminal in the French port of Calais, after a last minute surge in bookings.
Claudia, a 42-year-old German who lives in London but is currently on holiday in southwest France, called Britain's move an "absolute nightmare".
"Even if we wanted to we could not come back in time. Eurotunnel is sold out for any slot after midday," she told AFP.
French junior minister for European affairs Clement Beaune said it was "a British decision we regret and which will lead to a reciprocal measure".
He said he "hoped for a return to normal as soon as possible".
The Netherlands, which was also added to the quarantine list, said it would now advise against all non-essential travel to Britain, though arrivals from the UK will not need to quarantine.
Monaco and Malta and Caribbean island states Turks & Caicos & Aruba were also added to the list.
- 'Quarantine roulette' -
French student Antoine, 23, had to rush back to Bristol, south-west England, where he is at university -- paying 125 euros ($148) to change his ticket and cutting short his holiday by three days.
"I'm a waiter in a small café near college, I can't afford to spend 14 days in the house," he said at London's St Pancras railway station after getting off a Eurostar train.
Britain's badly-hit tourism sector also criticised the move.
"The UK needs a more sustainable long-term plan for the resumption of travel than quarantine roulette," said a spokesman for Heathrow Airport, the country's busiest hub.
Scientists at Britain's Joint Biosecurity Centre advised the latest measures be taken after French cases per 100,000 people rose above 20. On Thursday, France saw 2,669 new coronavirus infections, its highest daily number since May.
Britain announced 1,441 new cases Friday, its highest 24-hour tally in two months.
The UK had no quarantine measures in the early stages of the pandemic but in June imposed a blanket self-isolation requirement on all arrivals.
Weeks later it carved out "travel corridors" which exempted travellers from certain countries from quarantine.
However, the measures were reintroduced for arrivals from Spain in late July, catching airlines by surprise -- as well as thousands of Britons leaving for their holidays.
The government then reimposed quarantine for travellers from Andorra, Belgium and the Bahamas last week.
- 'Levelled off' -
With more than 41,000 deaths caused by the COVID-19 disease, Britain is the worst-hit country in Europe and Prime Minister Boris Johnson has been criticised over his handling of the crisis.
He said on Thursday that infection rates through July had "levelled off" and announced a further reopening of the economy in England.
Casinos and bowling alleys will be allowed to reopen and indoor theatres and music venues to resume with socially distanced audiences after being shut during the lockdown.
Pilot schemes of larger crowds at sporting events will be introduced following a two-week delay to the initial plans caused by a spike in cases.
However, the government also announced that the fine for those who "repeatedly flout face covering rules" will be doubled to a maximum of £3,200 ($4,200).
And Johnson warned he would act swiftly in any localised rise in cases, saying: "We will not hesitate to put on the brakes if required".