Covid-19 is the biggest health, social and economic emergency we have faced since the second world war. And while we’re only at the beginning of the process of halting its spread, we will be living with the consequences for many years to come.

Our first responsibility is to save lives. That means giving our fantastic NHS staff the time and resources they need. The biggest threat to life is if hospitals are overrun – with more patients requiring intensive care than there are beds available – as we’ve seen in Italy with devastating consequences. We’re already starting to see some London hospitals really feeling the strain.

That’s why it’s so crucial that we follow the expert advice – because it buys our NHS more time. Avoid social contact. Work from home if you possibly can – my team and I will. Don’t use public transport unless you absolutely have to. Do not attend any gatherings. Avoid places of worship. Pubs, clubs, gyms, cinemas and theatres should all now be closed. Restaurants and cafes must be takeaway or delivery only. Leave your home only if you really have to – to buy food and other essential items, to take a walk or exercise at a safe distance from others.

Life has changed and we all have to learn to live very differently for a while. We all have to learn how to use technology to keep in touch with loved ones. We’re going to become experts on the latest must-watch TV series!

We have a huge responsibility to look out for the elderly and vulnerable. That means Mother’s Day this year will be like no other. If you know someone who needs help, reach out. Set up a regular call. Ask if you can pick up their shopping and leave it on their doorstep. Please don’t buy any more food than you need. There is no shortage and there will always be enough to go around – if we only take our share.

We don’t know how long this will last. It will probably be many months. But we are not just doing this for our own health. We are doing it for our vulnerable loved ones who could die if we don’t – and for our heroic NHS and social care staff who need our help.

We also have to mitigate the economic impact of coronavirus. Without further decisive and immediate government action, thousands of businesses will go bankrupt and millions of people will be left unemployed, in poverty or homeless. We have a once-in-a-generation responsibility not to let that happen.

This virus is not the 'Chinese virus'. It does not respect national borders and will affect every country on Earth

The biggest barriers to following the expert advice are economic ones. People cannot be forced to choose between their health and being able to pay the rent and put food on the table. The government must ensure that businesses don’t go under and that not a single person is left permanently unemployed or pushed into poverty, loses their home, or is evicted or left homeless as a result of coronavirus.

The unprecedented measures outlined by the chancellor last week demonstrate he has grasped the severity of the situation – with a job guarantee scheme that should keep millions of people employed, hundreds of billions of pounds available in loans and grants to businesses, and the easing of restrictions on welfare access.

But let me be clear – these announcements alone will not be enough. The government must get the financial support already announced into bank accounts immediately so it can get into people’s purses and pockets. And the scale and scope of the economic response will need to increase if the pandemic lasts longer than the government hopes.

I am particularly worried about the millions of self-employed, freelances and those that work in the gig economy. Their income has not been secured. This must be rectified on Monday. And we must not forget those in our society who have the least: rough sleepers. I am working with the government on urgent measures to help them.

We also need further urgent reform of the welfare system. If someone says they need financial support in order to survive then they must get it without delay. That includes removing the “no recourse to public funds” condition and increasing emergency funding for local authorities and community organisations to help those in immediate need.

And we need a coordinated global economic response to the coronavirus. This virus is not the “Chinese virus”. It does not respect national borders and will affect every country on Earth. With Donald Trump rejecting the traditional leadership role of the US, responsibility for bringing world leaders together falls to us and other European leaders. It’s time for the British prime minister to show leadership.

We all have a role to play to ensure we halt the spread of coronavirus, protect our NHS, save lives and ensure that nobody is left unemployed, in poverty or homeless. Our nation has not seen a challenge of this scale for more than 70 years. We must rise to it.

Sadiq Khan is mayor of London