There were chaotic scenes at airports and ferry terminals across Europe this summer as Brits rushed to get home before quarantine rules – sometimes announced just hours before taking effect – kicked in.

One group of holidaymakers even chartered a boat across the Channel to beat the deadline for arrivals from France after missing the last ferry.

As it stands, anyone arriving in the UK from overseas must isolate for two weeks when they get here. If you’re symptom-free at the end of that time, you can end isolation – and you don’t need to take a coronavirus test.

Passengers from some countries are exempt, but that list is constantly changing as the government gets new information about local outbreaks overseas.

It was reported in late August that airline bosses had written to the Health Secretary Matt Hancock to say that the current quarantine policy is hampering the economic recovery and “leaves those who have travelled abroad unable to return to work, prevents business travel, and suppresses inbound tourism.” They called instead for a much shorter quarantine period, bookended by testing.

And there is some evidence – including from the government’s own modelling – that shorter isolation periods combined with testing could be just as effective as the current regime.

So why is the government sticking with the 14-day quarantine?

Why not do airport testing?

Asked why the government hadn’t rolled out testing at airports, the Health Secretary Matt Hancock told BBC Breakfast this morning: “If you test on day one on return, the scientists reckon we find about only 7 per cent of the total cases, so you still have to quarantine.”

That figure seems to come from a report prepared by Public Health England for the government’s SAGE committee meeting on 18 June.

The idea is that you can have the virus for several days before there’s enough in your system to show up on a lab test. That means someone who tests negative at the airport on arrival might have the virus and pass it on to others, even before symptoms develop (if they ever do).

Mr Hancock went on: “So this country, we’ve introduced this quarantine programme policy, and I know that it was controversial when we introduced it. But by God, I’m glad that we did because if you see the cases going up in France, in Spain – even in Germany – the case numbers are going up and we’ve had to, in the cases of France and Spain, take that action to have the quarantine policy in place.”

The PHE report certainly supports the idea that some quarantine is needed, and that airport testing will miss the vast majority of infected people.

Could the quarantine period be shorter?

But what Mr Hancock didn’t mention is that the same research finds that the quarantine period could be reduced from the current 14-day level without significantly increasing the number of infected people entering the community.

According to that PHE model, a seven-day quarantine which involved testing travellers five days into their isolation would prevent 85 per cent of “infectious entries” into the community.

A ten-day quarantine including a test after eight days would stop 96 per cent.

And it’s not just PHE. A draft paper (which has not yet been peer-reviewed) by the London School of Hygiene and Tropical Medicine reached nearly-identical results.

“We find that a quarantine period of at least 5 days, with a single PCR [laboratory coronavirus] test on the final day of quarantine, results in a reduction of over 80 per cent in both the number of infectious persons entering the community and the transmission potential of those persons,” the researchers wrote.

Meanwhile, they said “a 7-day quarantine with a test on the final day can reduce infectious entries by an average of 94 per cent”.

Commenting on the paper, Andrew Freedman, Reader in Infectious Diseases at Cardiff University told the British Medical Journal that the study “provides a strong argument in favour of shortening the quarantine period from the current 14 days to eight days, by performing a test on day 7 after arrival.”

He added: “This would have a very significant benefit to the individual traveller, as well as the travel industry as a whole.”

Mark Woolhouse, Professor of Infectious Disease Epidemiology at the University of Edinburgh, told the BMJ that the research “injects some much needed quantitative rigour into the ongoing policy debate around quarantining international travellers”.

“This is a welcome illustration of the principle that testing can be used to reduce the need for quarantine,” he said.

Importantly, the government’s current 14-day policy does not require travellers to get tested before the end of their self-isolation, unlike the shorter quarantine periods modelled by PHE and the London School.

We asked the Department of Health why it had implemented a 14-day quarantine period when models from PHE and the London School both find that shorter quarantine periods with tests at the end would be almost as effective at reducing the number of infectious people entering the community.

And given recent reports that show testing capacity in some parts of the country is under strain, we also asked the Department whether they were sticking with the longer quarantine period to avoid putting further pressure on testing.

A government spokesperson told FactCheck: “We are taking clear and decisive action to slow the spread of the virus and save lives. We keep the data for all countries and territories under constant review, and if the public health risk of people returning from a particular country without self-isolating becomes too high we will not hesitate to remove countries from the travel corridors exemptions list.

“Work is ongoing with clinicians, the devolved administrations and the travel industry to consider if and how testing could be used in the future to reduce the self-isolation period. Any potential change to the testing for arrivals would need to be robust in minimising the chance that positive cases are missed.”