Watch LIVE: the government's coronavirus press conference
17 March 2020, 15:27 | Updated: 17 March 2020, 17:07
Watch the government's coronavirus daily public briefing - the feed will appear here once it begins.
The entire UK population is being urged to follow unprecedented peacetime measures to try to control the spread of coronavirus.
The Prime Minister is asking everyone to avoid pubs, clubs and theatres, stop all non-essential contact and travel, and work from home if possible.
Mr Johnson has also told those with serious underlying health conditions to remain in self-isolation.
Read more: what is an underlying health condition?
Read more: Coronavirus updates LIVE