When Dominic Cummings appears in front of a parliamentary committee on Wednesday, the former aide is expected to attack Whitehall's institutional structure, a lack of government transparency in the pandemic, and the Prime Minister himself.
In a still growing Twitter thread, the former aide has laid out his critique of how the government handled Covid-19. He says herd immunity was 'literally the official plan' in March, and that a detailed response was 'bodged amid total & utter chaos.'
But how much damage can he do the PM? The Conservatives are just coming out of a successful local election campaign, the country is on course for social restrictions to end on 21 June, and the latest YouGov poll shows just 14 per cent of Brits trust Cummings. Isabel Hardman speaks to James Forsyth and Katy Balls.