DOMINIC Cummings has launched a ferocious broadside against his former boss accusing Boris Johnson of pursuing a secret policy of herd immunity to battle Covid-19 that would have led to “catastrophe”.

The Prime Minister’s former top adviser also claimed lockdowns could have been avoided if someone “competent” had been in charge.

And Cabinet Office officials were yesterday said to be worried that Cummings would reveal Johnson missed key coronavirus meetings because he was working on a biography of Shakespeare, the money from which he needed to fund his divorce from Marina Wheeler, his second wife.

The Prime Minister is said to have missed five Cobra emergency committee meetings at the beginning of the coronavirus crisis.

Cummings unleashed the assault ahead of his evidence to Wednesday’s joint hearing of the Commons health and science committees.

In a social media onslaught he said the “shocking truth” was that herd immunity was the Government’s plan until less than a fortnight before the first lockdown. It was abandoned only when ministers were warned it would lead to “hundreds of thousands choking to death” on hospital wards.

The former Downing Street aide also accused the Government of doing “very badly” on mass testing, a failure that meant lives were “needlessly lost”.

READ MORE: Boris Johnson 'missed key Covid meetings to work on Shakespeare book'

Cummings claimed Health Secretary Matt Hancock peddled “bullshit” when he denied that was ever the plan in March last year. He said the belief that Britain would have achieved herd immunity by September 2020 “was literally the official plan in all documents, graphs and meetings until it was ditched”.

He also attacked the media for accepting the Government’s denials: “Media generally abysmal on Covid but even I’ve been surprised by one thing: how many hacks have parroted Hancock’s line that ‘herd immunity wasn’t the plan’ when ‘herd immunity by September’ was ‘literally the official plan in all documents/graphs/meetings’ until it was ditched.

“Yes the media is often incompetent but something deeper is at work: much of SW1 (the Westminster postcode) was happy to believe Hancock’s bullshit that ‘it’s not the plan’ so they didn’t have to face the shocking truth. Most political hacks believe in ‘the system’...” Cummings said that in the week beginning March 9, “No 10 was made aware by various people that the official plan would lead to catastrophe. It was then replaced by plan B. But how ‘herd immunity by September’ could have been the plan until that week is a fundamental issue in the whole disaster”.

Chief scientific adviser, Sir Patrick Vallance, appeared to suggest on March 13 that herd immunity was one goal, but two days later Hancock said it was “not a goal or strategy”. The first lockdown was not imposed until March 23, a delay Cummings will claim was down to Johnson’s indecision.

Home Secretary Priti Patel denied herd immunity had been original policy, telling the Andrew Marr Show: “Absolutely not. Our strategy was always about protecting public health, saving lives and protecting the NHS.

“Absolutely all colleagues involved in those meetings and discussions, working with the chief scientist and the chief medical officers, absolutely recognised that from the very difficult discussions that we had.

“At the time of a crisis, when government is making very, very tough decisions, difficult decisions, we put public life and protecting the public at the forefront of all those decisions.”