Up to 200 British citizens trapped in Wuhan will be offered repatriation to the UK, Matt Hancock has said, as cases of coronavirus continued to mount in the Chinese city.

The health secretary told the House of Commons that the government was “rapidly advancing” plans to help citizens leave, and he urged any Britons in Hubei province to contact the Foreign Office.

He said those who chose to return to the UK would be asked to self-isolate even if they had no symptoms of the viral pneumonia caused by coronavirus.

More than 1,500 people have arrived in the UK on flights from Wuhan since 10 January, and it has emerged that the government has been able to trace only a small minority. It has email addresses for 10% and hopes the rest will hear of the new advice to self-isolate through the media.

The Department of Health said those who had arrived from Wuhan in the last 14 days should stay home and keep away from close contact with other people. The government does not propose a strict quarantine.

The government has been criticised for not having acted sooner to help UK citizens leave Wuhan, where streets are deserted and supermarket shelves are emptying. Other countries including France and Japan have already moved to get their citizens out.

French citizens are to be offered a place on a flight this week. On arrival in France, they will be placed in quarantine for 14 days.

It has been suggested the virus may be transmissible before symptoms show, though some experts say this is unlikely and that if it does happen, people will probably contract a mild form of the bug.

In the UK, 73 people have now been tested for the novel coronavirus and all have been cleared.

Hancock told MPs: “Coronaviruses do not usually spread if people don’t have symptoms, but we cannot be 100% certain. From today we are therefore asking anyone in the UK who has returned from Wuhan in the last 14 days to self-isolate, stay indoors and avoid contact with other people, and to contact NHS 111.

“If you are in Northern Ireland you should phone your GP. If you develop respiratory symptoms within 14 days of travel to the area and are now in the UK, call your GP or ring 111 informing them of your symptoms and your recent travel to the city. Do not leave your home until you have been given advice by a clinician.”

Hancock said the health department was working with Border Force, airlines and others including universities and cultural organisations to try to make contact with people who had flown in from Wuhan recently. He said there were 1,460 people “we are seeking to locate”.

Officials said self-isolation meant staying at home, not going to work and keeping away from others, as you would if trying to avoid passing on a heavy cold. Public Health England initially said it was safe for people who were self-isolating to leave their homes to buy food, for example, but later changed their advice, telling people to ask friends or family to buy it or to get it delivered.

It is not known how many of the 200 Britons known to be in Wuhan will choose to come back to the UK, and discussions are ongoing about how to get them out.

“We are working to make an option available for British nationals to leave Hubei province due to the heavy travel restrictions and increased difficulty of accessing consular or medical assistance,” a Foreign Office spokesperson said. “The safety and security of British nationals is our number one priority. We continue to monitor developments and are in close touch with the Chinese authorities.”

Those who return will be asked if they have somewhere to live where they can self-isolate. It is yet to be decided how they will be accommodated if not.

Hancock made it clear that the request for people to keep away from others was a precautionary measure. “Coronavirus presents with flu-like symptoms including a fever, a cough, or difficulty breathing. The current evidence is that most cases appear to be mild,” he said.

“However, this is a new disease and the global scientific community is still learning about it. I have therefore directed Public Health England to take a belt and braces approach, including tracing people who have been to Wuhan in the past 14 days.”