A Foreign Office spokesman said: ‘In light of the latest medical information, including reports of some person-to-person transmission, and the Chinese authorities’ own advice, we are now advising against all but essential travel to Wuhan.

‘The safety and security of British nationals is always our primary concern, and we advise British nationals travelling to China to remain vigilant and check our travel advice on gov.uk.’

It comes after officials in Wuhan asked residents not to leave the city unless there are special circumstances, in an attempt to contain the spread of the virus, according to Chinese state media.

Meanwhile, all direct flights from Wuhan city to Heathrow will be subjected to enhanced monitoring.

The Department of Health and Social Care (DHSC) said precautionary measures are being put in place after cases of the virus spread to other parts of the world.

More than 440 cases of coronavirus have been confirmed in Hubei province, of which Wuhan is the capital, and officials have said at least 17 people have died there.

There are three direct flights a week from Wuhan in China to Heathrow Airport, and under the new measures, planes will be taken to an isolated area of Terminal 4.

The captain of each flight will tell passengers during landing to let a flight attendant know if they feel unwell.

As of yet, there are no plans to introduce blanket temperature screening of all passengers, a spokesman for the DHSC said, as the incubation period for the illness can be as long as five days.

However, all passengers on each flight will be given a leaflet explaining how they can seek help if they become unwell while in the UK.

A statement from the DHSC said: ‘We have been carefully monitoring the situation in Wuhan for some time and are ready to put in place proportionate, precautionary measures.

‘From today, enhanced monitoring will be in place from all direct flights from Wuhan to the UK.

‘The enhanced monitoring package includes a number of measures that will help to provide advice to travellers if they feel unwell.

‘For those travelling back directly from Wuhan, this includes a port health team who will meet each direct flight aircraft to provide advice and support to those that feel unwell.’

The move comes as Public Health England (PHE) upgraded the risk to the UK population from coronavirus from ‘very low’ to ‘low’.

Dr Nick Phin, deputy director of the National Infection Service at PHE, said: ‘This is a new and rapidly evolving situation where information on cases and the virus is being gathered and assessed daily.

‘Based on the available evidence, the current risk to the UK is considered low.’

A handful of cases have been identified abroad, including in Japan and the US, but there have been no reported cases in the UK.

The World Health Organisation has delayed its decision on whether to declare an international public health emergency over the outbreak.

Professor Neil Ferguson, director of the Medical Research Centre for Global Infectious Disease Analysis, said the estimated number of people infected with coronavirus in Wuhan is around 4,000, with a range between 1,000 and 9,700.

Asked whether it was possible the virus had already reached the UK, Prof Ferguson said he could not rule it out.

He said: ‘We can’t rule out that possibility.

‘Border screening, and in this case, in the UK, alerting the health system is not 100% foolproof – there could be a mild case.

‘The UK is not a major destination of visitors travelling out of Wuhan around the world though.

‘So I would say it was unlikely, but can’t be completely sure.’

A spokesman for Heathrow said: ‘The welfare of our passengers and colleagues is always our main priority and we are working with the Government to support the implementation of enhanced monitoring measures as a precaution.’