U.K. Prime Minister Boris Johnson’s former top aide, Dominic Cummings, announced he would monetize some of his blog posts about his time in 10 Downing Street by offering subscriptions.

Cummings said on his website on Thursday that a lot of his writings about the Covid-19 pandemic will be free, as will “some stuff on my time in No10.” But other material will be available only to paying subscribers.

“More recondite stuff on the media, Westminster, ‘inside No10’, how did we get Brexit done in 2019, the 2019 election etc will be subscriber only,” Cummings wrote. “Subscribers will also get some extra features like community/regular ‘ask me anything’, and a serious dissent section — I’m interested in the best arguments against what I say.”

Cummings -- one of the key architects of Brexit -- was Johnson’s most powerful adviser until his acrimonious parting of ways with Johnson in November. Since then, he’s turned on his former employer. During a seven-hour parliamentary session he said the prime minister wasn’t fit to lead the country.

The former aide’s detailed knowledge of the inner workings of the U.K. administration and its handling of the pandemic last year make his blog posts compulsory reading for the Westminster media.

Now they’ll have to fork out to get the juiciest details: Cummings offered annual subscriptions at 100 pounds ($142), monthly ones at 10 pounds a month and “founding member” subscriptions at 200 pounds a year. As a taster of what may be to come, Cummings said: “I will expand here soon on the evidence I gave to MPs and publish evidence.”

“The core of the British state collapsed in spring 2020,” he wrote. “This systemic dysfunction continues.”