The medical officers have urged the Government to take action and “plan for all eventualities”. They did add, however, the risk to individuals has not increased despite the threat level being raised. 

Health experts made the announcement following a meeting with the World Health Organisation emergency committee in Geneva on Thursday night.

In a letter, the medical officers said: “We have been working in close collaboration with international colleagues and the World Health Organisation to monitor the situation in China and around the world.

“In light of the increasing number of cases in China and using existing and widely tested models, the four UK Chief Medical Officers consider it prudent for our governments to escalate planning and preparation in case of a more widespread outbreak.

“For that reason, we are advising an increase of the UK risk level from low to moderate. This does not mean we think the risk to individuals in the UK has changed at this stage, but that government should plan for all eventualities.

“As we have previously said, it is likely there will be individual cases and we are confident in the ability of the NHS and HSC in Northern Ireland to manage these in a way that protects the public and provides high-quality care.”

The officers are professor Chris Whitty for England, Dr Frank Atherton for Wales, Dr Catherine Calderwood for Scotland and Dr Michael McBride for Northern Ireland. 

Despite the threat level now being increased to moderate, approximately 150 British national will return to the UK from Wuhan. 

The group had been stuck in the city – the centre of the outbreak – and had been blocked from returning. 

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Despite declaring an international emergency, he did praise China for how it has dealt with the spread of the disease. 

“Let me be clear. This declaration is not a vote of no confidence in China.

“On the contrary, WHO continues to have confidence in China’s capacity to control the outbreak.”

Although he praised CHina’s efforts in containing the virus, the death toll rose to 170 on Thursday. 

Moreover, a total of 7,736 were diagnosed as being infected with the disease. 

Although the death toll has risen, the WHO also insisted they opposed “restrictions on travel” to and from China. 

On Wednesday, British Airways had grounded all flights to the country. 

In the UK, 161 people tested negative for the virus as of Thursday. 

Those returning to the UK on Friday, they will arrive at RAF Brize Norton in Oxfordshire before being quarantined for 14 days on the Wirral.