BORIS JOHNSON: I now imagine Covid WAS brought on by a lab leak. The Chinese owe us correct solutions and our Government ought to begin demanding them

You what? I said to my team in Number Ten, as they explained the origins of Covid. What did you say they were doing?

Yuk, I said. Yuk and triple yuk. As they described the practices in Wuhan, I was enraged and disgusted.

As an explanation for the emergence of this appalling disease, it seemed only too believable.

And, as it happened, I was about to have a call with Xi Jinping, and I had the chance to ask.

This was February 18, 2020, when it still seemed possible that Covid would be mainly a Chinese phenomenon. So, I began the call by commiserating with the President for the suffering of the Chinese, and by congratulating him on his efforts to contain the disease.

He was grateful for my sympathies, and for UK kindness in sending China valuable supplies of personal protective equipment.

I know, it seems crazy now but, as I say, we hadn’t yet foreseen the full implications of Covid for the UK.

At this point in the call, I decided to go off script. It was time to talk about what really happened in Wuhan.

We all knew that for many, many years the Chinese have been doing weird stuff in the name of medicine. Why do they sell live bats at markets in China? Why do they sell pangolins? It isn’t that the Chinese particularly like the taste of the poor beasts. It is because they believe that these beautiful, endangered species have unique medicinal properties – and we are generally reluctant to tell the Chinese the truth: that the whole thing is a load of mumbo-jumbo.

You won’t make your wife less prone to nervous fits by feeding her roast pangolin. You won’t promote her lactation.

This scaly, armoured anteater is an extraordinary creature – the only mammal in the world, as far as I know, whose tongue is rooted in its pelvis.

But it’s just rubbish to believe that you can grind up its scales, put them in a soup, and somehow transfer their former rigidity to the erections of middle-aged Chinese men.

As for bats, there is no evidence at all for the weird traditional belief that bat faeces are useful for improving your eyesight.

These ideas are not just batsh**, but dangerous batsh**.

So, it seemed eminently plausible, as I spoke to Xi, that my officials were right: that the Chinese habit of using so-called wet markets to slaughter and sell rare animals – creatures outside the normal human food chain – had something to do with the origins of Covid.

I said that I hoped he agreed with me that this outbreak was a wake-up call. It was a clear sign, I said, that we needed to stop trading endangered species.

Well, Xi listened politely and then said vaguely that the origins of the disease were still unclear. I now think he was humouring me.

Xi was content to let me rave on about pangolins – because he knew about another institution in Wuhan, where they had been doing something far more disgusting than the wet markets, and far more dangerous.

The Chinese leader knew all about the Wuhan Institute of Virology. To believe – now – that Covid did not originate in that lab, you have to believe in all sorts of outrageous coincidences. You have to believe it was pure fluke that the new bat-like coronavirus emerged in Wuhan, where they just happened to have the world’s foremost laboratory for the study of bat-like coronaviruses.

You have to believe that it was simply a matter of chance that this particular lab was conducting highly controversial ‘gain of function’ experiments – that is, playing around with the genetic make-up of the virus so as to make it more infectious to human beings.

You have to shut your eyes to the fact that when Covid hit us, nine of the closest genetic relatives of SARS-CoV-2 were in a freezer in the Wuhan lab.

As science journalist and author Matt Ridley has pointed out, this laboratory was notoriously lax in its biosecurity regime.

What they were doing was risky enough. They were taking spike genes from SARS-like viruses found in bats and then putting them in the ‘backbones’ of other viruses to make them up to 10,000 times more contagious to human cells and humanised mice.

Then they weren’t doing enough to make sure that the premises were properly sealed, to contain the chimera within.

To believe that the Wuhan lab was innocent you need a truly gargantuan appetite for coincidence. I am sorry, but I no longer find it credible.

Over the past year or so, a growing number of reputable public bodies have finally come out in favour of the lab leak theory: the CIA, the FBI, the German intelligence agency, and others.

I remember being amazed when I was first told about the Wuhan lab and what it was up to.

Repeatedly, I asked the scientists and diplomatic experts: how can you be so sure about this wet market stuff?

I wondered then – and I still wonder – why they were so dogmatic. Why did they dismiss the lab leak theory when it was obvious that a mutant and highly contagious coronavirus had cropped up in the very city where they happened to be artificially creating mutant and highly contagious coronaviruses?

Looking back, I think there were a number of reasons why some UK scientists were so obdurate. On the whole, I expect they didn’t like the lab leak theory for the basic reason it was bad for science.

They didn’t want to be blamed for making monsters in test tubes. They didn’t want a backlash against their experiments – not least because that would mean a cut in their funding.

Above all, they didn’t like the lab leak theory – because it was so offensive to the Chinese.

The wet market theory was bad enough because of the implied criticism of Chinese customs: the habit of eating rare animals; the belief in traditional medicine and so on. But the lab leak theory was far, far worse: it implied negligence, criminal negligence, on the part of an emanation of the Chinese state.

It became clear early on that the Chinese regarded the theory as grossly insulting and defamatory – and since the Chinese have been long-standing funders of UK academic research projects, and since the Chinese authorities are ruthless in cutting financial support from those who say the wrong thing, or step out of line . . .

Well, I think you can see why British scientists, on the whole, found it much more convenient to believe in that fatal viral romance between a bat and a pangolin.

Five years on, it’s just not good enough. To prepare for the next virus, we need to know the origins of this one. The Chinese have still not handed over the Wuhan data sets from September 2019 onwards, and refused to cooperate properly with the World Health Organisation investigation.

This is contemptuous. No other country would be allowed to behave in this way.

Covid killed around 15 million worldwide, according to the UN. It cost about $16 trillion. It did great physical, moral, economic and social harm to this country. The Chinese owe us a proper answer. The British government should ask for one. Until we get one, the scandal will grow.