Britain is moving into the second of four phases in its battle plan against coronavirus, England's Chief Medical Officer Chris Whitty said on Thursday, after confirmed cases jumped across the country.
Britain has so far registered 90 cases of coronavirus, also known as COVID-19, which started in China, but has held off from introducing measures to restrict movement or to cancel events for fear of hurting the economy.
Prime Minister Boris Johnson has said he is optimistic that Britain is well prepared to cope with the spread of the virus, but early on Thursday regional airline Flybe became one of the first big corporate casualties of the outbreak.
The government set out its action plan earlier this week based on four stages - containing the virus, delaying its transmission, researching its origins and mitigating its impact.
Whitty, questioned by lawmakers, said Britain had mainly moved into the second stage of delaying transmission and was now considering measures to try to reduce the peak of an epidemic which officials are anticipating in the coming weeks.
"The original plan ... was very much predicated on the idea of 'if it could be controlled in China and contained everywhere else, this virus might go away'. I think the chances of that happening are now very slim. Slim to zero," Whitty said.
"As time goes by, we then may start to move into the more socially determined actions ... We've moved from a situation where we were mainly in contain ... to now we're basically mainly delay."
The government has said it could encourage home-working, cancel large-scale gatherings and possibly close schools to slow the spread of the disease and delay the peak of the outbreak until summer, when the health service is under less pressure.
Whitty also said, with older people more vulnerable to the virus, there may be measures to encourage them to stay away from public places, such as the upper house of parliament, the House of Lords.
But so far, the government has refrained from triggering those measures, with Whitty saying health officials would present ministers with various options for them to decide what combination would be a "sensible response".