Boris Johnson has come under fire for a number of comments he made during the CV19 pandemic.
The inquiry heard the UK’s top civil servant Simon Case say Mr Johnson “cannot lead” and was making government “impossible”.
Messages shared by Lee Cain, Mr Johnson's former director of communications, also suggested that he was "obsessed" with "older people accepting their fate".
Sir Patrick Vallance, who was the chief scientific advisor at the time, wrote in a notebook that the former prime minister was "obsessed with older people accepting their fate and letting the young get on with life and the economy going. Quite bonkers set of exchanges".
Last message to Dominic Cummings
Towards the end of Tuesday's session, Mr Johnson's former chief aide Dominic Cummings shared the final message he received from his boss, two days after leaving Number 10 in November 2020.
"You speak of briefings from team Carrie.
"She hasn't briefed anyone and my instructions to all were to shut the f*** up. How is any of us supposed to know where these briefings come from?
"Look at the claims made on behalf of allies of Lee [Cain] and Dom, that I'm out in six months, that I can't take decisions, that Carrie is secretly forging lockdown policy, and about a billion equally demented claims.
"Are you responsible for all that c**p? No. Then look at it from my point of view. This is a totally disgusting orgy of narcissism by a government that should be solving a national crisis.
"We must end this. That's why I wanted to talk and see what we can jointly do to sterilise the whole thing. But if you really refuse, then that's up to you."
Mr Cummings seemingly didn't reply, though confirmed there was an "orgy of narcissism" in government.
Scottish CV19 inquiry: Does Sturgeon have WhatsApp messages?
In Holyrood, former first minister Nicola Sturgeon refused too confirm or deny allegations that she deleted WhatsApp messages during the pandemic.
It was the first time that Ms Sturgeon spoke following the allegations.
She said she has "nothing to hide", and is in the process of writing her third statement to the inquiry.
“I will be very clear to the inquiry what I hold and what I don’t hold and why that is the case but let me say again, I wasn’t a member of any WhatsApp groups.
"I didn’t manage the Covid response by WhatsApp."
14,000 messages to be released
Ms Sturgeon's statement comes after it was confirmed that the Scottish Government would hand over 14,000 WhatsApp messages to the inquiry, including from current first minister and former health secretary Humza Yousaf.
Deputy First Minister Shona Robison said :"all requested messages held will be shared in full and unredacted by 6 November".
She added that it would "be for individuals to explain to the inquiries they have taken in relation to record retention".