Dominic Cummings is set to reveal further details about his time at the heart of Boris Johnson’s government, after setting up a profile on a prominent newsletter platform.
The site allows people to sign up for newsletter mailing lists on topics they have an interest in.
Mr Cummings said in a post on his profile that he would be publishing information on the COVID-19 pandemic for free, along with details of his time in Number 10.
But he added that insights about “more recondite stuff on the media, Westminster, ‘inside No10’, how did we get Brexit done in 2019, the 2019 election etc” will only be available to users who pay a £10 per month subscription.
Those who sign up will also have access to “extra features” like Q&A sessions.
“Subscribers will find out first about new projects that I make public,” the post said.
“Only subscribers can comment.”
Mr Cummings also said he would use the site to campaign for answers on the pandemic and the way the government responded to it.
In a post on his Twitter account, Mr Cummings urged campaigners calling for an immediate inquiry into the government’s handling of COVID to get in touch as he would “help campaign for free”.
And he said he would use the Substack profile to “expand” on the testimony he gave to MPs last month and publish evidence “to encourage MPs to take responsibility and force such an inquiry to happen as soon as possible”.
The development will not be welcomed in Downing Street, which has had to contend with numerous interventions from Mr Cummings since his departure.
In an appearance before MPs last month, he claimed that the prime minister treated coronavirus like a “scare story”, Health Secretary Matt Hancock should have been “sacked for lying”, and many ministers were “literally skiing” as the pandemic was developing early last year.
Mr Cummings also said he heard Mr Johnson say he would rather see “bodies pile high” than go into a third lockdown – something which the PM has flatly denied – and claimed it was “crackers” Mr Johnson had become PM as he was “unfit for the job”.
The health secretary faced the same MPs on Thursday and denied lying to the PM during the pandemic.
He said the government “has operated better in the past six months” since Mr Cummings left, adding that it was “telling” that he had not yet submitted any evidence to the committee to support his allegations.