Boris Johnson sparked security fears as he posted pictures of the UK's first ever digital-only Cabinet meeting online today - including details of how to join the conversation.

The Prime Minister, who is currently self-isolating in Downing Street after being diagnosed with coronavirus, tweeted an image of this morning's meeting, which went ahead completely using the Zoom app.

It raised eyebrows because in the corner of the screen-grab he shared with his two million followers was the 'room' ID for the meeting using the Zoom software.

But those trying to gain access many hours after the morning meeting had ended were scuppered because the meeting was also password protected - prompting people to immediately start guessing what it could be.

Mr Johnson (top left) led a more relaxed regime as they met remotely this morning, appearing via webcam in an open-necked shirt and jumper

But he raised eyebrows when he tweeted a screen-grab from the meeting showing his colleagues - and the room ID for the meeting using the Zoom software.

Downing Street said it was confident its communications links were secure, despite concerns raised about the apparent use of Zoom to conduct the meetings.

What security measures does Zoom have? Users of the Zoom video-conferencing app are given a code to enter the meeting 'room'. This number of between nine and 11 digits can then be shared with those the meeting host wish to join them. But things can get out of hand if people share these codes online on social media, allowing something called 'zoombombing', where mass groups of people can join a meeting as a joke or to disrupt it if they receive the code. However, there are additional steps that can be taken to block this. Private groups can also be set up so that they require an additional password to join. This means that even if the room code is shared accidentally, as in today's case, it is not possible to join the room. Additionally, a meeting can be set up so that no-one can enter before the organiser or chair. This means pranksters cannot 'sit' in a room waiting for others to log in. The chair of the meeting has the power to kick uninvited guests out of the room once they are in it. Advertisement

Last week the use of the software by Ministry of Defence staff was suspended last week while 'security implications' were investigated.

The Prime Minister's official spokesman today told reporters: 'I don't think we have named the particular video conferencing tool that we have been using, but as you would imagine we ensured that it was done in a secure way.'

Downing Street was 'following all necessary security procedures' and 'I am happy to say with confidence we were satisfied it was secure', the spokesman added.

Mr Johnson joined the country in going casual while working from home (WFH) today as he hosted the meeting from his isolated home in 11 Downing Street.

The Prime Minister and his top political team are usually dressed to impress when they arrive at 10 Downing Street for the regularly weekly discussion.

But Mr Johnson led a more relaxed regime as they met remotely this morning, appearing via webcam in an open-necked shirt and jumper.

He can be excused for dressing-down as he is currently halfway through a seven-day quarantine Downing Street, after testing positive for coronavirus last Friday.

And not everyone got the 'home casual' memo. Predictably, Commons Leader Jacob Rees-Mogg, a stickler for correct dress, was among those who still wore a shirt and tie for the 10.15am face-to-face.

Education Secretary Gavin Williamson, Business Secretary Alok Sharma and Northern Ireland Secretary Brandon Lewis joined him by dressing smartly.

But new Chancellor Rishi Sunak and Health Secretary Matt Hancock - who is also under quarantine - were happy to ditch the neckware.

And International Trade Secretary Liz Truss trumped the rest by making sure she had a Union Jack flag behind her as she took part in the call.

Mr Johnson posted a picture of th emeeting on Twitter, writing: 'This morning I chaired the first ever digital Cabinet.

'Our message to the public is: stay at home, protect the NHS, save lives.'

Social media users were quick to point out the presence of the meeting's ID code in the image.

But according to US firm Zoom, which built the software, the ID expired after the end of the meeting.

Additionally, the room was protected by a password.

The meeting of the UK's top ministers was held entirely via videolink after three of the four people who were in the room for last week's semi-remote meeting were struck by the virus or showed symptoms.

Mr Johnson and Mr Hancock have been under quarantine since testing positive last Friday.

Chief Medical Officer professor Chris Whitty, who dialed-in to today's meeting, is also been self-isolating with symptoms. He gave a presentation to last Tuesday's meeting in person.

A Downing Street spokeswoman said: 'Ministers all appeared on a single digital screen, in a meeting chaired by the Prime Minister.

The meeting was held entirely via videolink - which Mr Johnson has been using to communicate with aides since last's coronavirus diagnosis (pictured)

Asked about Mr Johnson's condition, Grant Shapps told BBC Breakfast: 'The Prime Minister is Good. He is chairing Cabinet later this morning and we will be dialling in via video, via Zoom.

'Only the Cabinet Secretary (Sir Mark Sedwill) and a small number of officials were in the Cabinet room itself, observing social distancing rules on keeping two metres apart.

'Updates on the Government's coronavirus response were given by videoconference by the Chief Scientific Advisor and the Chief Medical Officer.

'Cabinet discussed the work which is taking place to support the NHS, expand testing, safeguard jobs and repatriate British citizens who are stranded abroad.

'They thanked the NHS and frontline workers for all of their tremendous hard work.

'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.'

Concerns were raised about the use of Zoom last week after it was reported that the Ministry of Defence was examining it for possible security weeknesses.

But a Government spokesman said: 'In the current unprecedented circumstances the need for effective channels of communication is vital.

NCSC (National Cyber-Security Centre) guidance shows there is no security reason for Zoom not to be used for conversations below a certain classification.'

Earlier, Transport Secretary Grant Shapps had confirmed the meeting would take place via web video conferencing.

Asked about Mr Johnson's condition this morning he told BBC Breakfast: 'The Prime Minister is good. He is chairing Cabinet later this morning and we will be dialling in via video, via Zoom.

'He is in fine fettle.'

It came as 1,408 people are confirmed to have died in UK hospitals after testing positive for Covid-19, as of 5pm on Sunday.

But the true death toll of the coronavirus outbreak in the UK could be 24 per cent higher than NHS figures show, according to statistics released today.

Patients who had COVID-19 mentioned on their death certificates numbered 210 in England and Wales up to March 20, the Office for National Statistics revealed.

This was 24 per cent higher than the 177 deaths recorded by NHS England during the same time frame.

The Office for National Statistics (ONS) has launched a new data series adding in the numbers of people who have died with or after having COVID-19 in the community, including those who died in care homes or at home.

Coronavirus was not necessarily the cause of death for every one of the patients, but was believed to have been a factor.

Anyone who has the virus - for which at least 22,141 people have tested positive in the UK - mentioned on their death certificate will be included in the statistics.

This adds to the daily updates coming from NHS hospitals around the country where patients of all ages are dying in intensive care units.

Mr Johnson using Zoom to chat with ministers at last week's Cabinet meeting. He and Matt Hancock, who were both in the room together, have since tested positive for coronavirus

The meeting came amid growing pressure to get more protective equipment to health workers.

The Prime Minister has faced heavy criticism over shortages of personal protective equipment (PPE) for frontline NHS staff as well as the slow rollout of testing - issues which are likely to be discussed by ministers on Tuesday morning.

Former health secretary Jeremy Hunt has also voiced further concerns about the lack of testing in the UK after it emerged the Government had still not hit its target of 10,000 tests a day.

This is despite earlier claims by Mr Hancock that the target had been reached.

The World Health Organisation (WHO) has urged countries to 'test, test, test' as a key part of their strategy to beat the virus.

But officials have admitted the UK does not have the same capacity as other countries that are testing more, including Germany which is conducting around 70,000 per day.

Mr Hunt told the Guardian: 'The big advantage we now have is evidence that testing works in other countries.

'We can see that Asian countries have been spectacularly more successful than European ones in avoiding mass lockdown.'