Twelve more cases of coronavirus have been confirmed in the UK, bringing the total to 51.
Health Secretary Matt Hancock told the Commons the threat in the UK is "increasingly serious" as he said the number of people with the virus had risen from 39 to 51.
However, he stressed that the Government and the health service are "well-prepared" to deal with a continued outbreak.
He told MPs on Tuesday: "The situation facing the country is increasingly serious. Globally and at home the number of cases continues to rise.
“As of 9am today there were 51 confirmed cases in the UK and it’s becoming more likely that we will see widespread transmission here in this country."
On Monday the total number of cases in the UK rose by four to 39, before the jump of 12 on Tuesday.
Earlier in the day on Tuesday, it was announced that one in five employees could be too ill to work if the worst case scenario materialises.
The Government's battle plan announced that police would focus on "responding to serious crimes and maintaining public order”.
Mr Hancock added: “Our approach is to plan for the worst and work for the best.”
He told MPs the UK is “well-prepared for infectious disease outbreaks of this kind” and said the response remains in the containment phase.
He added: “Contain is about detecting the early cases, following up with close contacts, preventing the disease from taking hold in this country for as long as reasonably possible.
“This approach also buys time for the NHS to ramp up its preparations.
“If the number of global cases continues to rise, especially in Europe, the scientific advice is that we may not be able to contain this virus indefinitely.”
The number of coronavirus cases worldwide has shot past 90,000, with more than 3,000 fatalities.
One British person died after contracting the illness on the Diamond Princess cruise ship off the coast of Japan.
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The UK's Chief Medical Officer Professor Chris Whitty stressed that the “great majority” survive coronavirus, even among the elderly.
“Even for the highest risk group, the great majority of people will survive this," he said.
Professor Whitty added that there was a “significant ramp up” in the death rate of those infected with coronavirus who are over 80 years old.
