Now is the time for everyone to stop non-essential contact
with others, and to stop all unnecessary travel.
We need people to start working from home
where they possibly can.
Coronavirus began as a health crisis
but it has rapidly morphed into a political and national one.
For Boris Johnson this could well
be the biggest test he will face as prime minister.
It's not that long ago that he won that stonking
80-seat majority in December's general election,
where he promised to get Brexit done,
but also level up the country by tackling regional inequalities,
as well as reforming government, and the way things
are done in Westminster.
That has now all gone out of the window,
as everybody behind the doors of 10
Downing Street is entirely focused on how
to deal with this crisis.
Every decision Boris Johnson makes about coronavirus
is going to be a political one.
And every single one will be tested
as he is further scrutinised for the UK's approach to dealing
with this.
And if you ask, well, why are we doing this now?
Why now?
Why not earlier or later?
Why bring in this very draconian measure?
The answer is that we are asking people
to do something that is difficult and disruptive
of their lives.
And the right moment, as we've always said,
is to do it when it is most effective.
Boris Johnson has been under a lot of scrutiny
because the UK has taken a rather different approach
to other European countries such as Ireland, France, and Italy.
Whereas they, very early on, introduced dramatic social
distancing measures, the UK is still
relatively business as normal.
At the beginning of this week, schools were open,
restaurants were serving, and people were still
drinking in pubs.
We're expecting more social distancing measures
to come in, in the coming days.
We have been guided by the science,
and we will do the right thing at the right time.
Boris Johnson has relied on scientific experts
throughout this thing, being posed
with Boris and the boffins, as it's called,
with his chief medical officer on one side,
and the chief scientific officer on the other.
He's been relying on their advice,
and pushing out the more difficult questions to them.
But there's still been some missteps
from Downing Street in this.
The question of herd immunity has troubled Number 10.
It began by briefing to journalists
that this was what the UK was achieving, trying
to get as much of the population immune to coronavirus
as possible.
But as the disease spread more rapidly,
and there were fears the message was backfiring,
they've now had to U-turn on this policy,
with the health secretary saying at the weekend the focus is
on saving lives as much as possible.
We've done what can be done to contain this disease,
and this has brought us valuable time.
But it's now a global pandemic, and the number of cases
will rise sharply.
Indeed, the true number of cases is higher, perhaps much higher,
than the number of cases we have so far confirmed with tests.
Ultimately, this will be a political test
for Boris Johnson.
He's well known to the British public as a jovial sloganeer,
a campaigner through his time as mayor of London,
an MP, and prime minister who is able to inject
a sense of optimism.
But now he has to prove himself that he can govern
in the most testing crisis.
Nobody doubts the coronavirus will be the biggest test facing
British governments in modern political history,
and that is the same for Boris Johnson, too.
Over the next couple of weeks you're
going to see a lot more of the prime minister,
a lot more transparency for the government, as people
will see whether he can step up to this crisis.
So far, the reviews are he's done pretty well
in very testing circumstances.
But the circumstances are only going to become more testing,
and the questions and political decisions
facing Mr Johnson behind this door even more onerous.