British Prime Minister Rishi Sunak faces questions Monday over whether his "Eat Out to Help Out" scheme to help the struggling hospitality sector during the pandemic spurred the spread of Covid-19.
Sunak, who was finance minister at the time, is due to give evidence to the public inquiry into the UK government's handling of the crisis.
In a message disclosed earlier to the inquiry, one government scientific adviser, Angela McLean, called Sunak "Dr Death, the Chancellor" over concerns about the scheme.
Sunak's appearance follows Johnson's own grilling by the inquiry last week as his government faces a string of challenges ahead of a general election expected next year.
His evidence will re-focus attention on the economic cost of the UK's repeated Covid lockdowns.
Sunak's government-backed initiative encouraged people to visit restaurants in August 2020 by picking up a chunk of the bill.
The hospitality sector had been badly hit by lockdown policies which forced them to close.
"It was an effective way of ensuring that the hospitality industry was supported through a very difficult period," cabinet minister Michael Gove said on Sunday.
He said it was "entirely within the broad outlines of rules about social mixing that prevailed at the time".
The inquiry has already heard from prominent figures including Johnson's controversial ex-aide Dominic Cummings and Patrick Vallance who was the government's chief scientific adviser during the pandemic.
Vallance told the inquiry Sunak's scheme was "highly likely" to have spurred deaths.
One of his diary entries recorded Cummings saying Sunak "thinks just let people die and that's OK".
Sunak has denied the comment and highlighted that Vallance confirmed he did not hear him say it.
According to material understood to have been shared with the inquiry's main participants, Sunak told a journalist last year he had not been "allowed to talk about the trade-off" between the economic and social impacts of lockdowns and their benefits to suppressing the virus.
He also discussed the "problem" of empowering independent scientists on policy.
Sunak's inquiry appearance comes as his government struggles to regain the initiative after damaging criticism from a sacked minister and the resignation of another over a stalled policy to control immigration by deporting migrants to Rwanda.
Interior minister Suella Braverman, who was dismissed by Sunak last month, and immigration minister Robert Jenrick have told the premier his policies to stop the arrival of immigrants by small boats are not tough enough, sparking fresh party disunity.
The Conservatives, in power since 2010, are currently lagging well behind Labour, the main opposition party, in opinion polls.
A survey released by Ipsos last week found that 52 percent of voters now had an unfavourable view of Sunak. His approval ratings have fallen from minus nine in January to minus 28.
The political and financial fallouts of the pandemic have had far reaching consequences for the UK.
Johnson was forced from office last year after public anger at revelations about a series of Covid lockdown-breaching parties dubbed "Partygate".
Sunak's policy of subsidising the wages of workers hit by the pandemic, meanwhile, cost billions and has badly dented the UK economy.
Nearly 130,000 people died with Covid in Britain by mid-July 2021, one of the worst official per capita tolls among Western nations.