The prime minister is expected to warn there is “little doubt” Covid-19 will present a “significant challenge” for the UK as he finalises the government’s ‘battle plan’ to fight the disease.
Johnson had been dubbed a “part-time” prime minister by critics for failing to take charge of a Cobra meeting before this week.
Health Secretary Matt Hancock said it was now “inevitable” that the deadly virus would “become endemic” in the UK as it was announced on Sunday that 13 more cases of Covid-19 had been diagnosed.
It brings the total number of people to have contracted coronavirus in the UK to 36, with Scotland declaring its first case.
On Monday morning, it was revealed that a clinician at the Mount Vernon Cancer Centre was among the people who have tested positive for the virus.
The East and North Hertfordshire NHS Trust said the risk to patients was “very low” and that everyone who had been in contact with the clinician had been identified. The centre remains open.
Over the weekend, the number of deaths from the virus around the world surpassed 3,000 over the weekend.
The vast majority of deaths have been recorded in China, where the outbreak began. However, people have now died from coronavirus in 12 other countries, including South Korea, Italy, Iran and Japan.
The Cobra meeting will be attended by senior ministers as well as chief medical officer Professor Chris Whitty and chief scientific adviser Sir Patrick Vallance, as they ratify the government’s proposed countermeasures.
First Minister Nicola Sturgeon is also expected to take part.
The PM is set to tell those at the crunch meeting: “The number of coronavirus cases around the world is rising every day – and the UK is no exception.
“There now seems little doubt that it will present a significant challenge for our country.
“But we are well prepared, and the government and the NHS will stop at nothing to fight this virus.
“This battle plan lays out in detail the measures we could use – if and when they are needed.”
The Conservative Party leader has delegated to his ministers to lead the sessions since they were first put into action in January.
But Johnson took a more active role in dealing with the situation on Sunday when he visited a Public Health England lab in Colindale, north London, where tests are being carried out on suspected coronavirus samples.
The PM then headed to the Royal Free Hospital in Hampstead to meet with staff who are treating patients with the virus.
Emergency powers set to be unveiled this week to help combat the virus include suspending rules about the maximum numbers of children that a single teacher can be responsible for.
The temporary measures will also allow for emergency medical registrations to create a “Dad’s Army” of retired doctors to back up an already under-strain NHS.
In a sign of how far the government fears coronavirus could escalate, Secretary of State Hancock refused to rule out putting British cities on lockdown, in an echo of how China looked to first contain the virus to its Wuhan epicentre.
Hancock told the BBC’s Andrew Marr programme: “There is clearly a huge economic and social downside to (shutting down cities).
“But we don’t take anything off the table at this stage because you have to make sure you have all the tools available if that is what is necessary.”
The Liberal Democrats have called for post-Brexit trade talks with the European Union, which are due to start on Monday, to be postponed to allow ministers to focus on stopping coronavirus.
The pro-Brussels party also called for the transition period to be extended beyond December as a result of the growing global concern.
Acting leader Sir Ed Davey said: “During this gathering storm, the national interest surely suggests that the PM should seek an extension of the Brexit transition period and pause the trade talks.
“Then the NHS and local communities can get the funds and the focus they deserve, and the UK can talk to our European neighbours about how we can cooperate against the coronavirus which does not recognise national borders.”
A Mail on Sunday report suggested that parliament could shut its gates if the situation worsens, with the government considering banning all major public events.
And the Guardian reported that the local elections, scheduled for May 7, could be postponed as a result of mounting fears of a widespread outbreak.
But Downing Street sources pointed to comments made by the Health Secretary where he said the advice for the public would remain the same until scientists looked to convince ministers otherwise.
Hancock told the BBC the public should continue to “go about their ordinary business” for the time being.