British people need to stop non-essential contact and avoid clubs, pubs, theatres and all unnecessary travel as the coronavirus outbreak accelerates towards the fast growth phase, Prime Minister Boris Johnson said on Monday.

"Now is the time for everyone to stop non essential contact with others and to stop all unnecessary travel," Johnson said at a news conference in Downing Street.

"We need people to start working from home where they possibly can," he said. "And you should avoid pubs, clubs, theatres and other such social venues."

"It looks as though we are now approaching the fast growth part of the upward curve and without drastic action cases could double every 5 or 6 days," Johnson said.