As a steady stream of travellers -- the first to experience the policy -- emerged into Terminal Two's lofty international arrivals hall, they described disorganized scenes at immigration as people struggled with the new bureaucracy.

Some questioned its need while others doubted UK officials' ability to enforce the new two-week stay-at-home order for arrivals by air, sea and land, barring some exemptions including those coming from Ireland.

"I just think it's a bonkers idea," said a masked 52-year-old Dutch lawyer, who asked to remain anonymous, returning from a week-long trip to see his wife in Amsterdam.

"More people are ill and dying in the UK. Probably Europe should be protected from us. It's the law, you have to obey. But sometimes the law doesn't make sense," he told AFP. 

Sandra Gibson, 49, arriving back in Britain after three months in New York, said she would spend a week isolating before deciding whether to complete the full 14 days. 

"I'm ready to go out now! I don't think they're going to check it rigorously," she said, after completing a trans-Atlantic flight via Amsterdam.

Heathrow, normally Europe's busiest airport, has shuttered three of its five terminals due to minimal demand since Britain advised against all foreign travel and ordered a nationwide lockdown in late March.

However, the government did not follow various countries, such as the United States, by introducing restrictions on incoming travel, citing scientific advice that its impact would be minimal.

Britain has since registered the world's second highest death toll from the virus -- more than 40,000 in total, second only to the US -- but has now reduced its transmission rate dramatically.

That has prompted the government to insist now is the time for quarantine to prevent a spike in infections, pledging to review the measures every three weeks.

 

'It makes no sense' 

On Monday, flights were still arriving at Heathrow from numerous destinations, such as Miami, Atlanta and Toronto in North America and Rome, Hamburg and Helsinki in Europe.

Some arriving were more supportive of the new policy, which could see fines of up to £1,000 ($1,270, 1,120 euros) issued for non-compliance.

"It should have been done sooner," said Wendy Gordon, 67, from the West Midlands region of England, returning after getting stuck in Florida as the US locked down due to the virus. 

But as she waited to be collected by her husband, Gordon conceded the policy could prove problematic for many people, including business travellers or tourists.

"It's alright for me, I'm retired. I'll just go home and sit. But I can appreciate there [are] major problems," she said.

Meanwhile at the Eurostar terminal at London's St Pancras station, also eerily deserted, those arriving from the continent were similarly divided about quarantine's value.

Sylvain Preumont, 50, a business manager based in London who makes the round-trip from Paris weekly, said as a frequent traveller he was exempt but that he was no fan of the policy.

"It makes no sense," he said. 

"This measure was invented to reassure people... to please them, and then we realize that it is not feasible."

However, Fatima Camara, 31, an engineer planning to stay with friends for the 14 days said it was not "a bad idea".

"Especially since the borders have been open, and people have been able to move around," she added while waiting for her taxi with a friend.

"If we are responsible, we protect ourselves and others."