Dominic Cummings has launched a foul-mouthed rant against "useless f*****s" in the Conservative Party as he took aim at Boris Johnson's handling of the coronavirus pandemic.

Cummings, who spearheaded the 2016 Vote Leave campaign, appeared before the Covid inquiry just after former colleague Lee Cain suggested the ex-Prime Minister was the wrong person to respond to COVID-19.

The 51-year-old told Johnson his Cabinet ministers were “useless f*****s” as he went on to criticise then-Health Secretary Matt Hancock as a “proven liar”.

He separately labelled his former colleagues "useless fpigs, morons and cs".

Cummings suggested the explosive language might not have been expressed by everyone in Whitehall but the sentiments were widely shared.

"My appalling language was obviously my own but my judgement of a lot of senior people was widespread," he told the inquiry.

Cummings, who left Downing Street alongside Cain after a power struggle broke out in November 2020, went on to suggest the majority of the Government's power was not held within Cabinet ahead of the pandemic.

He instead claimed the Cabinet Secretary Simon Case, who found himself somewhat implicated in the partygate scandal, was more powerful than the Cabinet apart from the Prime Minister.

Cummings added: "The Cabinet Office over a long period of time has accumulated more and more power, formal and informal.

"It’s become incredibly bloated. It’s acquired huge numbers of people, huge numbers of teams. And particularly on the whole, the sort of deep state, national security side, crisis management, has become in all sorts of ways extremely opaque and effectively completely invisible to any political figure, including the Prime Minister.

"So it was extremely difficult to know in Number 10 who exactly in the Cabinet Office was doing what, whose responsibility it was, who were we supposed to talk to to get action and that was critical, particularly in the first couple of months (of the pandemic)."