A leading medical adviser to the Hong Kong government is urging the administration to maintain a ban on flights from Britain until at least the end of the month when it reviews the policy next week.

His advice comes despite calls for the measure to be dropped by stranded residents desperate to return home and students hoping to resume their studies in Britain.

British Airways (BA) will restart services from Hong Kong to London on Sunday, as the country intends to reopen schools and universities in spite of the worsening wave of Covid-19 infections and the emergence of a new, more virulent strain of the coronavirus.

“Our focus is on keeping crucial air links open where possible – bringing home customers currently abroad, transporting vital goods and ensuring those who are permitted to travel can continue to do so safely,” BA said.

Still, the timetable for a full restoration of flights between the Asian financial hub and the British capital remains unclear. A Food and Health Bureau spokesman told the Post the flight ban would be reviewed this coming week.

Flights between the two cities were halted indefinitely on December 22 in response to the discovery of the more infectious strain sweeping parts of Britain. All airlines with routes between the two places halted flights after the Hong Kong government announced aircrew who had been in Britain in the past 14 days had to quarantine for three weeks.

Professor David Hui Shu-cheong, a respiratory medicine expert at Chinese University and a key voice in the government’s response to the pandemic, said containment has worked so far, referring to the lack of community transmission of the new variant. A local team of infectious disease experts determined the strain was 75 per cent more transmissible than the one circulating in Hong Kong.

Lifting the ban hinged on how quickly Britain could stamp out the new strain, either through vaccination or social-distancing measures, Hui said. The government should extend the flight ban until the end of January and reassess the situation then, he said.

But about 400 Hong Kong residents have called on the government to establish a date for when the flight ban would be rescinded or a window for travel opened, and provide sufficient hotel space for the required three weeks of quarantining, given the shortage of affordable accommodation.

In an open letter to the authorities, they also questioned whether the ban was a breach of the city’s mini-constitution, the Basic Law, which guaranteed residents freedom of movement.

“We don’t think that it is proportional or reasonable [to keep the ban for so long] because the bans by other countries have been short term,” a representative for the group said. “Everyone else is allowing their citizens to come home.

“We don’t have a problem with the ban in principle, but we have a problem with the government not letting us come home. We understand there are risks and concerns, so that we have to protect the Hong Kong public in Hong Kong, but that needs to extend to people outside the city.”

Students in Britain who came home for the holidays are facing limited options in returning to their studies. The British government is pressing ahead with reopening schools and universities, in spite of recently recording about 50,000 new infections three days in a row – up from about 14,000 daily cases at the start of the month.

Hong Kong has identified three people as carrying the more infectious strain – which has also been found in South Africa – although all were recently returned travellers who were quarantined. As of Saturday, the city’s infection tally stood at 8,923 cases, with 150 related deaths.

Dr Leung Chi-chiu, a former chair of the Medical Association’s advisory committee on communicable diseases, also called for the ban to stay in place for now, given the city was still in the grip of the fourth Covid-19 wave, with few hospital resources to spare to fight a new foreign strain.

Leung suggested any repatriation of Hongkongers from Britain should be done using chartered flights to ensure infection control was watertight, similar to how the government brought back residents stuck in Wuhan in Hubei province, the first epicentre of the pandemic, and the coronavirus-hit Princess Diamond cruise ship docked in Japan.

He pointed to authorities’ strategy in July of quarantining arrivals from “high-risk” places such as India and Pakistan in government-run camps and said the practice should be adopted for residents arriving from Britain.

“When Hong Kong’s fourth wave is over, there will be more capacity in terms of manpower and resources to cope with potential imported cases from Britain,” he said.

The total capacity at eight quarantine camps is 5,914 units, with 3,168 spaces currently available.

But Dr Gilman Siu Kit-hang, associate professor at Polytechnic University’s health, technology and informatics department, believed the monitoring in place at the airport could catch most carriers.

The more virulent strain had not circulated widely in Hong Kong, he said, noting none of the 21 infected people in the cluster at United Christian Hospital in Kwun Tong carried it.

“This means the UK strain has not been spreading locally so far, and as long as we have a virus-proof detection system in place at the airport, we can allow some residents back in a safe way,” Siu said.

The suspension of one of the world’s most valuable air routes has also prevented freight from moving. British retailer Marks & Spencer has been struggling to keep its shelves stocked over the holidays as inventory is either stuck in Britain or diverted, which creates lengthy delays.

Although BA will this week fly passengers from Hong Kong to Britain, departures from Heathrow in London remain unavailable and the route remains cargo only. The carrier will fly twice as many pilots and cabin crew and not stay in Hong Kong to avoid quarantine rules.

Meanwhile, as the stranded Hongkongers in Britain pointed out, the ban on all arrivals from that country raises constitutional questions, with Article 31 of the Basic Law stating that residents enjoy freedom to enter and leave the region.

Chief Executive Carrie Lam Cheng Yuet-ngor cited that right in March when she ruled out banning Hong Kong residents from returning to the city.

But Mark Daly, a human rights lawyer, said the government would need to balance community and personal rights when it came to freedom of movement.

“It is a matter of balance and would not be an absolute right,” Daly said. “You can’t rely on Article 31 of the Basic Law and say ‘I can come and go as I please even if I’m a super-spreader’.”

But if the government had failed to elaborate on the need for the ban and neglected to explore alternatives, a legal challenge might have a greater chance of succeeding, he said.

The bureau declined to state the legal grounds for the travel ban when contacted by the Post, but reiterated the government had to be “resolute” and implement the measure to keep the more contagious strain out of Hong Kong.