Rishi Sunak is facing a challenge at the coronavirus inquiry over claims that a government scientist referred to him as "Dr Death" – and called his plan to stimulate the economy “Eat Out to Help Out the Virus”.
The inquiry was also told that Boris Johnson's then chief adviser in Downing Street, Dominic Cummings, claimed that Mr Sunak's views on coronavirus were: "Just let people die and that's okay."
Mr Sunak, who was chancellor during the pandemic, is the final witness to take the stand in the current phase of the inquiry - following on from Boris Johnson and Matt Hancock.
The inquiry's lead counsel Hugo Keith KC - who like Mr Sunak was educated at Winchester and Oxford - is expected to give the current prime minister a torrid time after a tetchy clash with Mr Johnson last week.
Mr Keith has been nicknamed "Hugo Hindsight" and accused of "knifing hapless public servants" at the inquiry, and being obsessed with X-rated language used in WhatsApp messages sent during the crisis.
The "Dr Death" slur against Mr Sunak was said to have been made by Angela McLean, now the government's chief scientific adviser, while the attack over Eat Out to Help Out was made by chief medical officer Sir Chris Whitty.
The "let people die" claim attributed to Mr Cummings appeared in the diary entries of former chief scientific adviser Sir Patrick Vallance, who has been strongly critical of Mr Sunak in his evidence to the inquiry.
Mr Sunak will be questioned on claims that Eat Out to Help Out led to a spike in COVID cases and excess deaths - and that scientists were not consulted before it was launched.
But in a defiant witness statement to the inquiry, the PM insisted: "Any suggestion that Eat Out to Help Out caused the second wave of infections is not borne out with reference to the discussions at the time."
Michael Gove strongly defended Mr Sunak on Sky News yesterday.
On Sunday Morning With Trevor Phillips, he was asked about Sir Patrick Vallance's claim that Eat Out to Help Out almost certainly increased the number of excess deaths.
Mr Gove said: "That's Patrick's view and I have enormous respect for Sir Patrick, having worked with him closely.
"However, I think it's important to say that the Eat Out to Help Out scheme was announced a month before it was implemented and in the period post-announcement and pre-implementation, it was not the case that there was a public critique of it.
"It was an effective way of ensuring that the hospitality industry was supported through a very difficult period. And it was entirely within the broad outlines of rules about social mixing that prevailed at the time."
In his evidence, former deputy chief medical officer Professor Sir Jonathan Van-Tam said Eat Out to Help Out - which provided 50% off the cost of food and non-alcoholic drinks - "didn't feel sensible" because it was encouraging exactly what officials had been trying to stop in previous months.
Mr Sunak is also expected to be asked about lockdown-sceptic views he expressed during the 2022 Tory leadership election campaign, when he claimed too much power was given to government scientists.
He had told the Spectator magazine in August 2022: "We shouldn't have empowered the scientists in the way we did. And you have to acknowledge trade-offs from the beginning.
"If we'd done all of that we could be in a very different place. We'd probably have made different decisions on things like schools, for example.
"Could a more frank discussion have helped Britain avoid lockdown entirely, as Sweden did? I don't know, but it could have been shorter. Different. Quicker."
In that interview, Mr Sunak also claimed many of his objections to draconian COVID rules were met with a "big silence" from government colleagues.
"Those meetings were literally me around that table, just fighting. It was incredibly uncomfortable, every single time," he said.
One of Sir Patrick's diary entries said of Mr Sunak at a meeting: "Pushes very hard for faster opening up and fuller opening up, getting rid of all restrictions. Repeats his mantra: 'We either believe in the vaccine or we don't.'"
Mr Sunak may also face questions over his WhatsApp messages, or lack of them.
He has told the inquiry that "having changed my phone a number of times over the last three years" he no longer has access to them.