Up to a fifth of the workforce may be off sick during the peak of a coronavirus epidemic in the UK, the government says in its latest plans.
Police may need to focus on only responding to the most serious crimes and maintaining public order if the virus spreads.
The military could also provide support to emergency services if needed.
Other possible measures include school closures, reducing large-scale gatherings and working from home.
Some non-urgent hospital care may be delayed to focus on treating coronavirus patients, while recently retired doctors and nurses may be called back to work.
At a conference, Prime Minister Boris Johnson said the government was committed to doing “everything possible” to “prepare for all eventualities” and its priority was keeping the country safe, as the number of cases in the UK rose to 39.
While the vast majority of patients will have a mild to moderate illness, similar to seasonal flu, a minority will require hospital care and a small proportion could die, the plans warn.
There are no estimates given in the plans but they do warn of an increase in deaths, particularly among vulnerable and elderly groups.
Young children can become infected and “suffer severe illness”, but overall the illness is less common in the under-20s.
It is possible an outbreak could come in multiple waves, the government said.
The prime minister said he “fully understood” the public concern about the spread of the virus and it was “highly likely” the UK would see a growing number of cases.
“That’s why keeping the country safe is the government’s overriding priority, and our plan means we are committed to doing everything possible, based on the advice of our world-leading scientific experts, to prepare for all eventualities,” Mr Johnson said.
He reiterated that the “single most important thing” people could do was wash their hands with soap and hot water for the length of time it takes to sing Happy Birthday twice.
“But at this stage… I want to stress that for the vast majority of the people of this country, we should be going about our business as usual,” Mr Johnson added.
The prime minister said schools should stay open “if possible” and follow advice from Public Health England.
Evidence suggested children were less likely to be infected and they were more likely to get mild symptoms, England’s chief medical officer Prof Chris Whitty added.
Closures would also bring “a considerable burden”, including on the NHS, as workers would need to stay at home to look after their children.
Mayor of London Sadiq Khan said there were currently no plans to postpone the London Marathon nor to restrict public transport.
Other measures in the plan include:
- Hospital discharges could be monitored to free-up beds, with appropriate care given in people’s homes.
- Helping businesses with short-term cash flow problems, including giving them longer to pay bills.
- A “distribution strategy” for the UK’s stockpiles of key medicines and equipment such as protective clothing, which will cover the NHS and could extend to social care.
- All government departments are to have a lead person for coronavirus.