Decision leaves tens of thousands weighing up huge choice without knowing why they should leave

The British government’s surprise announcement telling Britons to leave China “if they can” comes amid mounting international concern about the spread of coronavirus.

But the advice came with no detailed guidance about why the UK’s position had changed – making it unclear whether this was a political stance, or a position based on new medical guidance that British authorities have not shared publicly.

Other governments have cautioned against travel to China, or barred travellers who have made a recent visit. But the UK is the first country to advise its citizens to leave China, suggesting even greater concerns about the virus.

It is almost certain to anger Chinese authorities, who have already strongly criticised American and Australian bans on travellers from China entering the respective countries. It also puts tens of thousands of Britons living in China in an extremely difficult position.

Quick guide What are coronavirus symptoms and should I go to a doctor? Show Hide What is Covid-19? Covid-19 is caused by a member of the coronavirus family that has never been encountered before. Like other coronaviruses, it has come from animals. The World Health Organization (WHO) has declared it a pandemic. What are the symptoms this coronavirus causes? According to the WHO, the most common symptoms of Covid-19 are fever, tiredness and a dry cough. Some patients may also have a runny nose, sore throat, nasal congestion and aches and pains or diarrhoea. Some people report losing their sense of taste and/or smell. About 80% of people who get Covid-19 experience a mild case – about as serious as a regular cold – and recover without needing any special treatment. About one in six people, the WHO says, become seriously ill. The elderly and people with underlying medical problems like high blood pressure, heart problems or diabetes, or chronic respiratory conditions, are at a greater risk of serious illness from Covid-19. In the UK, the National health Service (NHS) has identified the specific symptoms to look for as experiencing either: a high temperature - you feel hot to touch on your chest or back

a new continuous cough - this means you’ve started coughing repeatedly As this is viral pneumonia, antibiotics are of no use. The antiviral drugs we have against flu will not work, and there is currently no vaccine. Recovery depends on the strength of the immune system. Should I go to the doctor if I have a cough? Medical advice varies around the world - with many countries imposing travel bans and lockdowns to try and prevent the spread of the virus. In many place people are being told to stay at home rather than visit a doctor of hospital in person. Check with your local authorities. In the UK, NHS advice is that anyone with symptoms should stay at home for at least 7 days. If you live with other people, they should stay at home for at least 14 days, to avoid spreading the infection outside the home.

For many, a decision to leave could have significant personal, financial and professional ramifications, as it seems increasingly likely that the outbreak may last weeks or even months, so any absence would be long-term.

Those who have set up or run businesses may worry about how they will operate without key staff. Students may be penalised for leaving a course if they need credits towards a degree, while employees with contracts may be penalised for breaking them.

Families with children in school may not be able to find them a place to study in the UK – or elsewhere – at short notice.

Those whose relatives do not hold UK passports are likely to be particularly anxious after watching the confusion over who would be allowed to leave Wuhan, the centre of the virus outbreak, on evacuation flights.

The British government has not said if it will offer any financial support to help them leave, any guidance on whether insurers might cover some costs, or advice on whether dependents could get fast-track help with paperwork to come to the UK.

Nor is it clear what support – if any – the government will be willing or able to offer those who decide to stay on despite the latest advice. It has already reduced the number of diplomatic staff and warned that its support for citizens in China could be affected.

Tuesday’s decision effectively leaves tens of thousands of people forced to weigh up a decision with huge consequences – without any real understanding of why they are being urged to leave now.

Those who were in the quarantined centre of the outbreak, Wuhan, have already been evacuated. Those who are left are likely to be asking if the UK authorities know or suspect the coronavirus is spreading widely elsewhere.