Eleven more cases of Coronavirus have been confirmed in the UK bringing total up to 51.
Health Secretary Matt Hancock said the threat of Coronavirus to the UK is "increasingly serious" but stressed the Government and the health service are "well-prepared".
In a Commons statement, he said: "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."
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.
"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."
Mr Hancock said: "Research is not just about developing a vaccine which we're actively pursuing, but which will be many months away at the earliest.
"Research is also about understanding what actions will lessen the impact of a Coronavirus including what drugs and treatments existing and new will help those who are already sick."
The fourth phase, mitigate, would happen "if Coronavirus becomes established in the UK population", he said.
"At that point it will be impossible to prevent widespread transmission so the emphasis will be on caring for those who are most seriously ill and keeping essential services running at a time when large parts of the workforce may be off sick.
"Our plans include not just the most likely case but the reasonable worst case. We will identify and support the most vulnerable and if necessary we will take some of the actions set out in today's plan to reduce the impact of absentees and to lessen the impact on our economy and supply chains."
Mr Hancock said: "We prepare for the worst and work for the best.
"We commit to ensuring that the agencies responsible for tackling this outbreak are properly resourced, have the people, equipment and the medicine they need and that any new laws they need are brought forward as and when required.
"This is a national effort, we need everyone to listen to and act on the official medical advice. We need employers to prioritise the welfare of their staff and the single most important thing that everyone can do and I make no apologies for repeating this, is to use tissues when you cough or sneeze and wash your hands more often.
"It's in your interest, your family's interest and in the national interest. We will get through this and everyone has a part to play."