Why have travellers from France been ordered to quarantine on entry into the UK?

France has recorded post-lockdown record highs of daily cases in successive days with 2,669 new Covid-19 infections reported on Thursday, up from 2,524 the day before. Both figures topped the 2,288 cases on Friday, another record since the country began to ease out of lockdown in May, followed by 2,184 infections on Saturday, 1,885 on Sunday and 785 on Monday.

Meanwhile, according to the European Centre for Disease Prevention and Control, France’s 14-day cumulative number of Covid-19 cases per 100,000 people reached 32.1 as of Thursday, compared with the UK’s 18.5. The steep rise in cases prompted Downing Street to announce it is removing France from its travel corridor list on Thursday evening, meaning travellers returning to the UK must now self-isolate for 14 days or face a fine.

How many British holidaymakers will this affect?

It is hard to put an exact figure on it but, with France the second most-popular holiday destination for Britons and August being peak season, it is likely the move will affect hundreds of thousands of travellers already across the Channel and those with future bookings. Paul Charles, the chief executive of the travel consultancy the PC Agency, told the Guardian earlier this week that his firm estimated there were as many as half a million British holidaymakers in France this week.

What are holidaymakers in France now meant to do?

Holidaymakers already in France face a choice of whether to scramble to return to the UK before the country is formally removed from the travel corridor at 4am on Saturday or else face having to quarantine for two weeks if they arrive back after.

Announcing the move, the Department for Transport said: “People currently in France … are encouraged to follow the local rules and check the FCO travel advice pages on GOV.UK for further information. The government is urging employers to be understanding of those returning from these destinations who now will need to self-isolate and has invested over £9bn to strengthen the welfare safety net, helping to ensure access for those in need.”

What about those who are due to travel soon?

The sudden restrictions will throw holiday plans into chaos for many UK travellers, with the Foreign and Commonwealth Office now advising against all non-essential travel to France.

The UK’s largest association of travel agents and tour operators, Abta, released a statement from its chief executive, Mark Tanzer, earlier on Thursday before the new travel corridor announcements were made in which he said: “Package holiday customers should be offered a full refund in the event of Foreign Office advice against all but essential travel to a destination at the time the customer is due to travel.”

He added: “The upholding of the protections of package holidays is in the long-term interest of members, notwithstanding the harsh trading conditions, and it will give reassurance to customers at a time when confidence is essential. Of course, members may well be able to offer affected customers alternative destinations or travel dates.

“Airlines not refunding remains a significant aspect of the refund issue. Recognising this from the outset, Abta has been doing all we can to help alleviate the cash flow problem for members. We have pressurised the aviation regulators to enforce airline refund obligations, and we introduced the mechanism of refund credit notes to allow time for airline refunds to come through.”

Why have cases surged in France?

France’s prime minister, Jean Castex, warned on Tuesday that the country had been going “the wrong way” for two weeks after a rise in infections.

Figures suggest there has been a disproportionate rise in cases for younger people, compared with older members of the country’s population. According to France’s Santé Publique agency, the Covid-19 incidence rate per 100,000 inhabitants in the 20 to 29 age group has risen to nearly 45 from 7 in early May.

Meanwhile, the incidence rate has also climbed from from 6.1 to 26.5 in the 30 to 39 age group. Over the same period, the infection rate among 80 to 89-year-olds halved, while in the over-90 age group it fell from 60 to 13.

France’s health minister, Olivier Véran, confirmed late last month that those testing positive were “younger than during the previous wave” of the virus, suggesting that “people in more vulnerable groups have doubtless remained more prudent” while “young people tend to pay less attention”.