Dominic Cummings has threatened to auction off a "crucial" Covid-19 document which would expose Boris Johnson's pandemic decision making.
Mr Cummings, perhaps best known by the public for breaking lockdown rules at the height of the pandemic, went on to argue on Twitter that lockdown should have been brought in "harder and earlier".
On Twitter, the former No10 aide claimed to have "the only copy of a crucial historical document from covid decision-making."
And he asked followers to vote on whether he should hand the document to the joint health and science committee ahead of a hearing next week - or auction it off for a Covid families charity.
The tweet was later deleted - and a further tweet suggested he had "botched options like an idiot."
He explained he would still give the documents to the committee if it was auctioned off.
Mr Cummings suggested auctioning the document as an "NFT" - a 'non-fungible token'.
Buying an NFT means you own a unique digital 'trading card' of something - but don't own the item itself.
Mr Cummings wrote on Twitter that the Government's Covid plan was supposed to be "world class" but turned out to be "part disaster, part non-existent".
He said public scrutiny was now essential to examine how the Government will respond to a variant of the virus which can escape vaccines.
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 on May 26.
Ahead of his appearance, Mr Cummings highlighted his concerns with the approach adopted in the early stages of the pandemic last year.
He wrote: "If you are going to have to do measures [like] lockdown to avoid health system collapse then the harder/earlier the better & the sooner they can be released.
"Pseudo 'lockdowns' without serious enforcement are hopeless: economic hit & people die anyway, nightmare rumbles on."
"One of the most fundamental & 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 taskforce to respond to new variants.
"The best hedge re a variant escaping current vaccines is public scrutiny of Gvt plans," he wrote.
"This will hopefully show it's been taken seriously.
"If not, better learn now that the Government has screwed up again than when 'variant escapes' news breaks."
Mr Cummings, who has seen the classified elements of the Covid-19 response, 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".
He also suggested that vaccines could have been developed faster if "human challenge" trials, where volunteers are deliberately infected with the virus, had begun immediately.
That could have meant "jabs in arms (in the) summer", he said, but the vaccine taskforce (VTF) was "constrained" in ways they should not be.
Human challenge trials only took place this year, but the development of vaccines was rapid in comparison with work on jabs for other diseases.
