The Chief Medical Officer for England Chris Whitty said he was reasonably confident that "probably around 1 percent of people who contracted the virus might end up dying, based on the Chinese experience".
He also said that it could be lower than that because there was no way to tell how many people had the illness but no symptoms, reports The Guardian.
On Tuesday, The UK government released a planning document setting out how ministers should deal with an escalating outbreak. The action plan envisages for scenarios ranging from a milder pandemic to a "severe prolonged pandemic as experienced in 1918" when the Spanish Flu killed 50 million worldwide.
UK Prime Minister Boris Johnson said it was "highly likely" the number of cases in the country would rise.
"I fully understand public concern, your concern, about the global spread of the virus … Keeping the country safe is the government's overriding priority."
Johnson said it was "too early to say" how many people would contract Covid-19.