An intensive care expert has explained how one person with coronavirus can infect 59,000 others – compared to 14 with flu.

Dr Hugh Montgomery, professor of intensive care medicine at University College London, illustrated how Covid-19 is three times more infectious than ordinary flu and the importance of social distancing to stem the spread of the disease.

He told Channel 4’s Dispatches programme: “Normal flu, if I get that, I’m going to infect on average, about 1.3, 1.4 people – if there was such a division.

“And if those 1.3, 1.4 people gave it to the next lot, that’s the second time it gets passed on.

“By the time that’s happened 10 times, I’ve been responsible for about 14 cases of flu.

“This coronavirus is very, very infectious, so every person passes it to three.

“Now that doesn’t sound like much of a difference, but if each of those three passes it to three, and that happens at 10 layers, I have been responsible for infecting 59,000 people.”

These figures are calculated by raising 1.3 and three to the power of 10.

Dr Montgomery also warned against anyone being complacent and ignoring the government’s advice on social distancing.

“I’m not going to play it down,” he said. “It’s going to be ugly, it’s going to be horrible for a large number of people – but it will be a small number of people who get properly sick and a smaller percentage of those again that need to come to an intensive care unit and we can save the lives of a large number of those people too.

“But please just remember that the best chance we can give for the people who did fall ill is if we have got enough beds and enough staff and enough kit to be able to be there for you.

“And if you are irresponsible enough to think that you don’t mind if you get the flu, remember it’s not about you, it’s about everybody else.”

The specialist said most people who get the illness will feel a bit unwell before they recover, but will spread it around if they do not self-isolate.

However, he added: “A few will get sick at about day 10 of their illness so they will need to come into a hospital and they will consume resources and time and people will look after them, quite rightly, and they will be monitored to see if they become really, really sick.

“Those people then come to an intensive care unit and that’s where if you’re critically ill your life gets saved, or not, and this is the issue.

“If we have got a limited number resource, which we have, a limited number of ventilators, a limited number of doctors, a limited number of nurses ... if we overwhelm that, we can’t provide that service of caring for these people properly.”

It comes after health secretary branded people flouting advice to stay two metres apart as “very selfish”.

Matt Hancock warned the government was willing to take “more action” if needed to stop coronavirus from spreading after crowds flocked to beaches and parks across the country over the weekend.

The UK’s death toll rose 355 on Monday as a further 46 people died after testing positive for Covid-19.