Senior civil servants "wanted" people to get COVID like chickenpox to build herd immunity, according to messages read out during an inquiry into the government's handling of the pandemic.
Sir Christopher Wormald remains the most senior civil servant in the Department of Health and Social Care (DHSC) - as he was in early 2020.
Messages he exchanged with Mark Sedwill - then the head of the Civil Service - were shown to the inquiry.
These were sent on 12 March 2020.
Lord Sedwill said: "I don't think PM & Co have internalised yet the distinction between minimising mortality and not trying to stop most people getting it.
"Indeed presumably like chickenpox we want people to get it and develop herd immunity before the next wave.
"We just want them not to get it all at once and preferably when it's warn (sic) and dry etc."
Sir Christopher responded: "Exactly right. We make the point every meeting, they don't quite get it."
A lot of time during the inquiry has been taken up on when the government change from planning to mitigate people getting the virus, to preventing the spread of the virus and locking down.
On 14 March, the then-health secretary, Matt Hancock, wrote in The Daily Telegraph: "We have a plan, based on the expertise of world-leading scientists. Herd immunity is not a part of it. That is a scientific concept, not a goal or a strategy.
"Our goal is to protect life from this virus, our strategy is to protect the most vulnerable and protect the NHS through contain, delay, research and mitigate."
On 23 March, Boris Johnson enacted lockdown.
Dominic Cummings, who was a political appointee by Mr Johnson, repeatedly criticised the Civil Service while he gave evidence to the inquiry.
On the same day as the civil servants were talking, Mr Cummings complained in a WhatsApp message that Lord Sedwill had been "babbling about chickenpox", adding "god f****** help us".
Speaking to the inquiry on Tuesday, Mr Cummings said Lord Sedwill told Mr Johnson: "PM, you should go on TV and should explain that this is like the old days with chickenpox and people are going to have chickenpox parties. And the sooner a lot of people get this and get it over with the better sort of thing."
In a post on social media, Mr Cummings responded to the messages published today.
He said: "The reason the [Lord Sedwill] suggested to the PM on 12/3 to tell the country to hold chickenpox parties - and me/Ben Warner said 'you must stop saying this' - is [Sir Christopher], *in charge of 'the plan'*, was telling him this was the f****** plan!!!
"Holy s*** this is truly atrocious and explains so much."
Sir Christopher, who was pushed by inquiry lawyers to explain the messages, said that it was a reference to herd immunity but argued it was "reflecting the state of the scientific advice at that point".
He said he had been "very, very loose in my reply" and that he had at the time been following the Scientific Advisory Group for Emergencies - Sage - advice.