Hundreds of British citizens being flown back to the UK from Wuhan on Thursday will be put in quarantine for two weeks on their arrival.
It is believed passengers will be required to sign a contract committing to the quarantine period.
It comes as British Airways suspends all direct flights to and from mainland China because of the coronavirus outbreak.
Australia, Japan, the US and EU nations are also repatriating citizens.
The virus has caused more than 130 deaths, spreading across China and to at least 16 other countries.
The UK government plans to fly 200 British citizens out from Wuhan, the centre of the new coronavirus outbreak.
They will be put in “supported isolation” for 14 days with “all necessary medical attention”, a Downing Street spokesman said.
He said the government would confirm the location they will be held in due course but offered no comment on reports it would be a military base.
“Our priority is to keep British nationals and their families together,” he added.
Those returning from other parts of China will not be affected, but have been advised to “self-isolate” for 14 days.
Health Secretary Matt Hancock will chair a meeting of the government’s emergency Cobra committee at 16:30 GMT.
Australia plans to quarantine its 600 returning citizens for two weeks on Christmas Island – some 2,000km (1,200 miles) from the mainland.
British Airways, which operates daily flights to Shanghai and Beijing from Heathrow, announced the suspension of flights to and from mainland China “with immediate effect” until 31 January while it assesses the situation.
A statement said: “We apologise to customers for the inconvenience, but the safety of our customers and crew is always our priority.”
Other airlines, including United Airlines, Air Canada and Cathay Pacific Airways, have already cancelled some flights to China.
What’s happening to people stuck in Wuhan?
Some Britons in Wuhan said they had not been told about the quarantine plan, with one man having refused his place on the flight for fear of spreading the disease.
Kharn Lambert told the BBC’s Victoria Derbyshire programme that the embassy said it is their own responsibility to arrange transport home and isolate themselves.
“I don’t want to put the health of regular, everyday British citizens at risk,” he said.
British lecturer Yvonne Griffiths, who is currently in a hotel in Wuhan, said she was told in the early hours of Wednesday morning that there would be a flight from Wuhan airport to the UK.
“We have to be there six to seven hours before the flight leaves, and we would have a screening from some health people here in Wuhan, and if we are not showing any symptoms then we’ll be able to board that plane,” she said.
“If we were to be suffering temperature or any other symptoms, breathing problems, then there seems to be a possibility of quarantining at this end.”
Another British man, Jeff Siddle, from Northumberland, said that he and his daughter had been offered seats on a flight on Thursday – but not his wife, who’s a Chinese national. China is not allowing its citizens to leave the country.
What about people flying back from China?
By Francesca Gillett, BBC News reporter, at Heathrow Airport
Passengers on BA’s last flight from Beijing walked into Heathrow Airport’s arrival lounge shortly after 15.30 GMT.
Some were wearing masks, others said they had just taken them off. Nearly everyone on the flight had been wearing one, passengers said – and staff at Beijing airport had carried out temperature checks.
Teacher Daniel Maloney, 50, is originally from Scarborough but lives in a village north of Beijing. He came back to the UK with his two children. His village is in lockdown, he said, showing a WhatsApp group where villagers shared concerns about how to access supplies.
Schools are shut at least until 17 February. “There’s only so many jigsaws we can do,” he said.
He had been stockpiling food and hired a driver to take the family to the airport early this morning. “The motorways were empty and there were about 20 people at the airport,” he said.
Mr Maloney has already booked a doctors appointment for his children back in the UK for later this week.
Also on the plane was Edinburgh University student James Marmol, from London, who has had to cut short his year studying abroad at Beijing’s Peking University.
“I was kind of surprised there wasn’t as many checks as I thought,” said Mr Marmol of the BA flight.
What’s the latest on the virus itself?
The number of deaths from the virus has risen to 132 in China, the Chinese National Health Commission (NHC) said on Wednesday.
Four cases have been confirmed in Germany, making it the second European country to report cases, after France.
The United Arab Emirates has also confirmed its first cases of the virus in a family who recently returned to the UAE from Wuhan.
In the UK, the Department of Health said on Wednesday that 130 people had been given the all-clear for the virus.
An expert from the NHC said it could take 10 more days for the outbreak to peak.
Like the similar Sars and influenza viruses, the new coronavirus is a particular risk for elderly people and those with pre-existing illnesses.
The sharp rise in cases is in part attributed to increased awareness, monitoring and testing in recent days.
One theory is that the virus, which can cause severe acute respiratory infection, may have emerged from illegally traded wildlife at a seafood market in Wuhan, the capital of Hubei province.
There is no specific cure or vaccine. A number of people, however, have recovered after treatment.
Which other airlines are suspending flights?
United Airlines has cancelled 24 US flights to Beijing, Hong Kong and Shanghai between 1 and 8 February because of a sharp drop in demand.
Cathay Pacific said it would cut flights to China from 30 January to the end of March, while Air Canada has also reduced its number of flights.
Indonesia’s Lion Air said it would be temporarily suspending flights from Saturday, affecting dozens of flights on routes to 15 Chinese cities.
Russia’s Ural Airlines said it had suspended some services to Europe popular with Chinese tourists, including Paris and Rome, because of the outbreak.
Other airlines are introducing measures aimed at reducing the chances of spreading the virus.
Taiwan’s China Airlines said it was encouraging passengers to bring their own beverage bottles, while Singapore Airlines was among those allowing crew to wear masks on China flights.
Who else is being evacuated?
New Zealand will cooperate with Canberra to bring its 53 citizens home alongside the Australian evacuees.
Some 200 Japanese nationals have been flown from Wuhan and have landed at Tokyo’s Haneda airport.
Around 650 others said they wanted to be repatriated, and the Japanese government said new flights were being planned.
According to Japanese media, several of the returnees were suffering from fever or coughs. All will be taken to hospital, regardless of whether they are showing symptoms.
Also on Wednesday, 240 Americans – including workers the local US consulate – left the city.
According to CNN, the evacuees might have to stay in isolation in an airport hangar for up to two weeks.
Separately, two aircraft to fly EU citizens home were scheduled, with 250 French nationals leaving on the first flight.
South Korea said some 700 of its citizens would leave on four flights this week. Both Malaysia and the Philippines also said they would evacuate their citizens in and around Wuhan.
Meanwhile, Hong Kong announced plans to slash cross-border travel between the city and mainland China.
Learn more about the new virus
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