IF you won’t say what’s broken, you won’t be able to fix it. On that principle, the government is not going to get a better grip on the Covid-19 crisis.

Just before Matt Hancock announced his latest reorganisation of test-and-trace, his department put out a press release saying: “NHS Test and Trace service results in line with the recognised metric of success for contact-tracing services across the world.”

So the system to chase the virus is working well. The Department for Health liked this factlet so much they said it twice. The same press release added that the contact-tracing service “is reaching over 79 per cent of all those who test positive, and 83.4 per cent of their contacts where contact details were provided, which is in line with the recognised metric of success for contact-tracing services across the world.”

So we have achieved an “international metric of success.” Except, as anyone who can do basic maths can see, we haven’t.

The Department of Health told me this metric is “a consensus among experts that 80 per cent of contacts need to be contacted and self-isolating for the system to be very effective.”

I traced it back to the government’s chief advisors, the Scientific Advisory Group for Emergencies (SAGE) who back in May, “discussed the test-and-trace system in development. It agreed that at least 80 per cent of contacts of an index case would need to be contacted for a system to be effective”

So that’s “at least” 80 per cent to be “effective.”

But If we only reach 79 per cent of those who tested positive, 83.4 per cent of their contacts is actually only 66 per cent of all “index case contacts” — because we lost contact with 21 per cent of all those who test positive before we even asked about their contacts . The correct sum is 83.4 per cent of 79 per cent — which works out at 66 per cent.

We are below the “metric.”

So where is the problem? The national contact-tracing service run by outsourcers Serco and Sitel are given the “non complex” cases to chase their contacts. And they are only reaching 57 per cent of their contacts.

By contrast the public-sector contact chasers — the Public Health England in-house teams and the local authorities dealing with “complex” cases reached 97.9 per cent of their contacts.

So the public sector teams did much better. It’s there in the figures, but it is not recognised by the minister. Which is why he has put Dido Harding, the Tory peer with no medical experience — who manages the privatised contact tracing — in charge of the whole operation and, at the same time, abolished Public Health England which supplied the one bit of contact tracing that works best.