Coronavirus: Government knows it must act fast and credibly

"The government is about to involve itself in the lives of millions of people in ways we haven't seen since the war," one senior figure in government said after Cabinet this morning.

You can only imagine the mood around the table as ministers absorb the scale of what we face as a country and the scale of the responsibility they hold.

Whether it is urging people not to travel abroad, providing huge emergency assistance to particular industries, or telling people to stay at home, according to that Cabinet minister, we are living through a massive change in the relationship between government and the public that could last for many months.

What the prime minister said barely two weeks ago, that the UK would "likely face a challenge", has very rapidly turned into the biggest peacetime task any modern government has faced - managing a very serious international health emergency and trying to stave off the worst of a potential economic emergency too.

Boris Johnson told his colleagues this morning: "We are engaged in a war against the disease which we have to win."

As I write the details of exactly what the Chancellor will promise to prop the economy are still being thrashed out.

Less than a week ago, Rishi Sunak unveiled a programme that made sick pay more generous, promised to scrap business rates this year for some small firms and make it easier to claim benefits for people who were at risk of losing their income.

But as the pace of the outbreak has accelerated, so too has the potential for enormous economic damage.

So expect later today to hear about plans for bigger interventions.

There is clearly urgent demand from business large and small to help.

But the priority right now may be reassurance as much as a radical final blueprint.

As during the financial crisis, perhaps the details of what will be announced this afternoon matter less than the promise of a comprehensive approach that genuinely will provide support to every part of the economy and every part of the country.

It is also worth remembering that the financial system itself is in a much, much more robust state than it was then.

But there is no spreadsheet that can capture the potential for disruption and hardship here, no set of calculations that can accurately predict what will happen to the economy.

There is no end date to the epidemic, no precise sense of when we will hit the peak of the infections, although Whitehall sources still believe it is maybe a couple of months away.

But the government knows that it has to act, very fast, and very credibly.

One senior Treasury source said: "There aren't options to let this float around - we have to take control because it is so unprecedented."

In the last 24 hours, Downing Street's instructions to the public to protect everyone's health changed at breakneck speed as new scientific data emerged.

Now the government's approach to how the country makes its living is changing too.