As the second Covid winter wave built, messages appear to show Mr Johnson’s faith was faltering in the ability of lockdowns to control the virus.

On 15 October 2020, Mr Johnson said he was “rocked” by analysis that the average age of those dying was over 80, adding: “That is above life expectancy. So get Covid and live longer.”

The messages were sent one day after the three-tier system of restrictions was rolled out in England.

Mr Johnson goes on to say “I no longer buy all this NHS overwhelmed stuff”. In other words, the PM seems to have been losing faith in the central argument for lockdown his government had been making for months – namely, that it was necessary to limit the number of cases to a level the health service could cope with.

When Mr Cain asks how his new outlook would change the government’s policy, Mr Johnson says: “It shows we don’t go for nationwide lockdown.”

But on 31 October, just over a fortnight after the exchange, the government did announce another lockdown in England.

Mr Johnson has not responded to the evidence heard in the inquiry so far but is due to give evidence later this year. He is “co-operating fully” with the inquiry, his spokesman said this week.