Garvan Walshe is a former national and international security policy adviser to the Conservative Party.

Yesterday, Greg Clark held a masterful session of the Science and Technology Committee hearing into the UK’s response to the coronavirus. This was democratic deliberation at its best. Careful posing of questions designed to elicit information, informed contributions by the MPs present (who observed social distancing guidelines), free of the grandstanding to which these committee’s are prone.

Some of this has to do with the seriousness of the moment; the rest down to Clark’s serious and empirical personality. At a time of emergency like this, his talents should be deployed in government fighting this epidemic; though it is partial compensation that he has been able to shed light on an area where policy has shifted, communication has been less than transparent and, it appears, vital time has been lost.

The implications of that time being lost were set out by Neil Ferguson of Imperial college, who gave evidence at the hearing. Now that the lockdown has been imposed in the UK, he told the committee that deaths from the coronavirus were “unlikely to exceed 20,000”.

While this is a huge improvement on the 200,000 to 500,000 deaths that his model predicted, had the Government continued with its previous policy that classified a 60 per cent infection rate as “desirable”, it needs to be put in perspective.

Total deaths in Hubei, China, which has about the same population as the UK have so far been recorded as being about 3,100. Italy, with about the same population as the UK, but with a significantly greater acute bed capacity, has so far recored 6,000 deaths.

Now that Italy has been under lockdown for between two and three weeks, the rate of transmission of infection there has slowed, and the epidemic there may well have peaked. If it declines at the same rate it grew (a reasonable, though not always correct, assumption), a rough estimate of about 12,000 deaths there would be expected.

It is not unreasonable to conclude that the UK could be on track for an Italian-style scenario, in which overall intensive care capacity is sufficient, but it is not located in the right places, producing real pressure in places where demand is high and capacity low. This was entirely avoidable.

The evidence presented at the committee points to a number of serious errors of judgement made in the UK in its response to the outbreak. To see which, it is necessary to identify the constraints on a response to a disease for which there is no vaccine or treatment.

Two kinds of measures are required to combat the epidemic: supportive care to keep patients alive while their immune system fights off the infection, and the reduction of opportunities for the infection to spread. The constraint on the former is the health system’s capacity to provide that care: in this case, intensive care capacity that keeps people breathing even as the virus attacks their lungs.

On the latter, it is the ability to identify people with the virus so they can be cared for and isolated: in short, venitlators and testing. If the former capacity is exceeded, doctors are unable to treat everyone who need intensive care, and are forced to make agonising choices about who is to be left to die, as is happening in Bergamo. If the latter capacity is exceeded, then mass social distancing measures are needed, as is happening in most of Europe and parts of the United States.

South Korea and Taiwan, which built up experience from their own failures in the SARS epidemic, were ready with testing and tracking sytems that have contained the spread of the virus, even though, because of proximity, they had huge exposure to China. In Europe, Norway and Germany were able to expand their testing capacity in time, which has slowed down the spread of the disase and have kept fatality rates low (because they identify a greater number of cases).

A study by the scientists at the London School of Hygiene and Tropical Medicine, for example, estimates the UK is only reporting six per cent of all cases, compared to Germany’s 69 per cent. If these figures are accurate, the total number of cases in the UK would be around 130,000 (compared to about 8000 detected at time of writing).

While limited testing capacity explains why the UK is confining testing to hospitals, and the SARS experience explains why South Korea and Taiwan responded so quickly, neither of these factors explain why the UK was not able to grow coronavirus testing capacity as quickly as, for instance, Germany, has. Overall, Britain’s performance is on a par with Spain’s and Italy’s. Why?

The second matter was the decision to delay the introduction of social distancing measures until this week. A major factor revealed by yesterday’s testimony was the desire to avoid a second wave of infections as measures imposed early were then relaxed.

But so too, and it featured in communications from the Chief Scientific Officer, was the notion that the severity of this second wave could be reduced by failing to suppress the epidemic through social distancing measures. This policy was changed following Professor Ferguson’s report, but why was it necessary to wait for it, when the evidence from Italy was that even detected cases in the thousands could overwhelm the health system of Lombardy, one of the richest regions of Europe?

It seems that Britain’s system of public health policymaking is at last doing the right thing, and adopting international best practice, but it cannot afford to take so long to incorporate international lessons as the epidemic progresses. Crucial weeks have been wasted already. It’s vital no more are.