A commercially chartered jet was due to depart from the Chinese city on Thursday morning to bring around 200 British nationals home.
But the government now says the evacuation will no longer take place, adding it was continuing work to “urgently to organise a fight to the UK as soon as possible”.
The delay has been caused because Chinese officials are yet to grant permission for a charter flight to depart, the Independent understands.
“We are doing everything we can to get British people in Wuhan safely back to the UK,” a Foreign Office spokesperson said. “A number of countries’ flights have been unable to take off as planned.”
“We remain in close contact with the Chinese authorities and conversations are ongoing at all levels.”
Once they do return, passengers may be asked to sign a contract saying they agree to being placed in quarantine before they board the plane. Anyone who does not wish to sign could be asked to stay behind.
The passengers could be held at a military base once they arrive home, the Department of Health and Social Care said.
A No.10 source declined to name the airport at which the plane will arrive in the UK or where passengers will be kept in isolation, with medical attention, for 14 days.
There is room on board for all those eligible to return from Wuhan, but Chinese authorities are not allowing dual or single-nationality relatives such as spouses to join the flight, No.10 said.
“Our priority is to keep British nationals and their families together and we have urgently raised this with the Chinese authorities, including the foreign secretary speaking to his Chinese counterpart yesterday,” the source said.
“It is Chinese policy that those with Chinese dual or single nationality can’t leave Wuhan through an assisted flight.”
Health secretary Matt Hancock wrote on Twitter: “We are working hard to get British nationals back from Wuhan. Public safety is the top priority. Anyone who returns from Wuhan will be safely isolated for 14 days, with all necessary medical attention.”
The World Health Organisation has reconvened a meeting of its emergency committee due to the increasing number of cases and evidence of person-to-person transmission of the virus.
It comes as Finland confirmed its first case of the virus, affecting a Chinese traveller from Wuhan. They remain in in Lapland’s central hospital in the north of the country, while a further 15 people who came into contact with the patient are being monitored.
Dr Michael Ryan, the executive director of the WHO health emergencies programme, told a press conference in Geneva that the Chinese government deserves “huge credit” for its response and transparency regarding the “extraordinary challenge”.
Director-general Tedros Adhanom Ghebreyesus added: “The fact that to date we have seen only 68 cases outside China, and no deaths, is due in no small part to the extraordinary steps the government has taken to prevent the export of cases. For that, China deserves our gratitude and respect.”
Dr Michael Head, a senior research fellow in global health at the University of Southampton, said: “The quarantine will be precautionary. Over 100 tests have been carried out in the UK so far, with all of them negative for coronavirus infection. However, this new restriction may reflect the increase in cases in China over the last 24 hours, and ongoing concern about cases coming into the UK and the potential for person-to-person transmission.
“This is a different type of coronavirus, compared to what we saw with SARS, so it will behave a little differently. There have been more cases in China but so far with a lower death rate than the SARS outbreak. A pandemic is typically called by the World Health Organisation after there has been sustained transmission across many countries. Though there have been cases reported in several countries now, we’re not quite at that stage of sustained transmission yet.”
British Airways has already suspended all direct flights to and from mainland China, where as many as 50 million people have been put on lockdown by authorities to try to contain the virus. Lufthansa, one of the world’s largest airlines, has ruled out flights until the end of February.
Japan and the US have airlifted hundreds of their citizens from the city as the death toll from the coronavirus outbreak has hit 132. A chartered flight evacuated 201 US citizens from the region on Wednesday. It arrived in southern California, where the citizens will be placed in temporary housing.
Confirmed cases of the virus have also increased to more than 6,000, overtaking the confirmed cases of Sars over the same time period during the 2002-2003 outbreak which killed more than 750 people in 17 countries worldwide.
A total of 130 people have been tested for the virus but no cases have been confirmed in the UK and the risk to the public has been described as low.
Visitors to Wuhan who have arrived back in the UK have been told to self isolate and to contact NHS 111.
Meanwhile, the World Athletics Indoor Championships, scheduled to take place in Nanjing, China, in March have been postponed until 2021. The official World Athletics body said it had considered relocating the event to another country but decided against that option because the spread of the virus outside China could have forced another postponement.
Doubts have also been raised over the staging of the Chinese Grand Prix, due to take place in April.
Additional reporting by agencies.