Boris Johnson, speaking via videolink from self-isolation, has warned members of his Cabinet that the coronavirus pandemic in the UK is "going to get worse before it gets better".
But the prime minister reassured a depleted Cabinet Room that the situation "will get better", as he hammered home the importance of social distancing.
“The PM said the rising death toll in recent days showed the vital importance of the public continuing to stick to the social distancing guidance which has been put in place by the Government, based on scientific and medical advice," a Downing Street spokesman said.
“The PM said that the situation is going to get worse before it gets better – but it will get better.”
Concerns had been raised about the use of Zoom to conduct the meetings after the use of the software by Ministry of Defence staff was suspended last week while “security implications” were investigated.
But Downing Street said it was confident its communications links were secure after the first Cabinet meeting where all ministers dialled in as part of the effort to limit the spread of coronavirus.
Mr Johnson posted a tweet after the meeting showing he and 24 other videolinks communicating via Zoom.
Following the meeting, it was announced that NHS visas are going to be extended until the end of the year.
Children eligible for free school meals will benefit from a national voucher scheme allowing them to continue to access meals whilst they stay at home.
Education Secretary Gavin Williamson has announced schools can now provide every eligible child with a weekly shopping voucher worth £15 to spend at supermarkets while schools are closed due to coronavirus.
In the Cabinet Room itself there was only Cabinet Secretary Sir Mark Sedwill and a small number of officials watching the prime minister - most senior ministers are believed to have tuned in via videolink.
Last week, four people attended the meeting in person – including Mr Johnson, Health Secretary Matt Hancock, Cabinet Secretary Sir Mark Sedwill and chief medical officer Professor Chris Whitty – while others dialled in on the Zoom app.
The PM and Mr Hancock have since tested positive for Covid-19, while Prof Whitty is self-isolating after developing symptoms.
In today's meeting updates on the government’s coronavirus response were given by videoconference by Chief Scientific Adviser Sir Patrick Vallance and England’s Chief Medical Officer Whitty.
Earlier, Education Secretary Williamson said Mr Johnson’s workload was undiminished despite him having to self-isolate after becoming infected.
“The energy and the amount of work that is coming out of No 10 and the flat that he is isolated in has not tapered away,” he told the PA news agency.
“I think self-isolation has increased the prime ministerial work rate. He is absolutely all over it.”
Mr Williamson rejected criticism that Mr Johnson became infected because ministers ignored their own rules of social distancing.
“We all recognise that London and particularly central London has been a real hotspot for the virus,” he said.
“Just the length of time the virus takes, most people will have picked up the virus before these new rules have been put into place, but it goes to highlight the importance of the new rules and the importance of people adhering to those rules.”
On Monday Foreign Secretary Dominic Raab - who has been agreed as stand-in prime minister, should Mr Johnson become too ill to work - said his boss had shown "vigour" in video conferences, despite his diagnosis.
Mr Raab, who says he is “feeling terrific”, told the daily coronavirus press conference: “The prime minister chaired the 9.15am meeting and was full of vigour and was giving us the leadership we need, and we are a united Cabinet team in terms of getting the country through this crisis."
In a video post announcing his coronavirus diagnosis, Mr Johnson told his Twitter followers he had developed a temperature and a persistent cough.
He added: “I’m working from home and self-isolating and that’s entirely the right thing to do.
“But, be in no doubt that I can continue thanks to the wizardry of modern technology to communicate with all my top team to lead the national fightback against coronavirus.
“I want to thank everybody involved and, of course, our amazing NHS staff.”
Coronavirus: Everything you need to know