Dominic Cummings' allies claim he is plotting "revenge" on Boris Johnson and won't stop until he is no longer Prime Minister, according to reports.
The former top aide is said to have got top Westminster officials sweating as they brace for the former Downing Street to give evidence about it pandemic response.
The Prime Minister's former right hand man has already issued a series of Twitter broadsides against Downing Street's handling of the crisis in recent weeks.
Mr Cummings, who left Downing Street in November after a behind-the-scenes power struggle, is due to give evidence to MPs on the coronavirus response later this month.
The influential Westminster player's public appearance is said to be making top officials nervous, as they are wary of his past access to classified elements of the UK's Covid response.
Sources told The Times that Mr Cummings wants to put across his version of the events of the past year - but is also intent on using his evidence to 'destroy' former boss Boris Johnson and exact 'revenge.'
“He’s basically going to try and napalm him,” one ally of the former top aides told the newspaper.
Another said: “He wants revenge... He thinks Boris is a clown who failed to learn the lessons of the first lockdown and even when we had all the data and knew what was going to happen he did nothing.
"He’s not going to stop. He’s not going to get bored. I don’t think he’ll stop until Boris is no longer prime minister.”
Downing Street spent the latter part of last year embroiled in a series of briefing wars amid a top personnel shakeup that peaked with Mr Cummings' high-profile exit.
There had been a public clamour for the aide to lose his job before then amid outrage over his series of lockdown-breaching trips.
Ahead of his appearance before MPs, Mr Cummings has been tweeting his concerns about the approach the government adopted in the early stages of the pandemic.
He has blamed the Government's secrecy over the coronavirus response for the "catastrophe" in spring 2020
He wrote on Twitter last week: "One of the most fundamental and unarguable lessons of Feb-March is that secrecy contributed greatly to the catastrophe.
"Openness to scrutiny would have exposed Government errors weeks earlier than happened."
He questioned why MPs were accepting the "lack of a public plan now" for the vaccines task-force to respond to new mutant strains of the virus, such as the Indian variant emerging in infections hotpots including Bolton and Blackburn with Darwen.
"The best hedge re a variant escaping current vaccines is public scrutiny of Gvt plans," Mr Cummings wrote.
"This will hopefully show it's been taken seriously.
"If not, better learn now that the Gvt has screwed up again than when 'variant escapes' news breaks."
Mr Cummings suggested the Government could make 99% of vaccine plans public without risk as national security concerns are "almost totally irrelevant to the critical parts of the problem".
