Dominic Cummings has made a career out of defying conventional wisdom and trying to upset the established order.
Boris Johnson’s closest political adviser has been in and around the upper reaches of government and the Conservative Party for nearly two decades but made his name as the mastermind of the successful 2016 Vote Leave campaign to take Britain out of the European Union.
It was Mr Cummings who came up with the campaign’s “take back control” slogan and spent most of its budget on data analysis and targeted social media ads.
He has never been a member of the Conservative Party and has little time for what he sees as some of the time-servers and publicity addicts that populate the Commons benches.
He has a similarly dismissive attitude to the media or at least those whose job it is to “doorstep” people outside their homes. In recent weeks, he has delighted in giving surreal answers to their earnest questions.
A longstanding Eurosceptic who cut his campaigning teeth as a director of the anti-euro Business for Sterling group, Mr Cummings’s other passion is changing the way government operates.
He grabbed headlines last month when he posted an advert on his personal blog for “weirdos and misfits with odd skills” to work in government.
The career civil servants and “public school bluffers” in Whitehall are singularly ill equipped to take decisions about complex issues, he has argued at great length on his blog.
Instead, he believes, mathematicians and data scientists should be given a far bigger role – and he has made an effort to educate himself in these fields.
It has been reported his WhatsApp profile lists his priorities as “Get Brexit Done, then Arpa”.
This is a reference to the Advanced Research Projects Agency set by the US in 1958 that led to the creation of Silicon Valley.
Mr Cummings is a native of Durham, in the north-east of England. His father, Robert, was an oil rig engineer and his mother, Morag, a teacher and behavioural specialist.
He went to a state primary school and was then privately educated at Durham School. He graduated from Oxford University with a first-class degree in modern history and spent some time in Russia, where he was involved with an ill fated attempt to launch an airline, among other projects.
After a stint as campaign director for Business for Sterling, he spent eight months as chief strategy adviser to then Conservative leader Iain Duncan Smith.
He played a key role in the 2004 campaign against an elected regional assembly in his native North East.
In what turned out to be a dry run for the Brexit campaign, the North East Says No team won the referendum with a mix of eye-catching stunts – including an inflatable white elephant – and snappy slogans that tapped into the growing anti-politics mood among the public.
He is then said to have retreated to his father’s farm, in County Durham, where he spent his time reading science and history books in an effort to attain a better understanding of the world.
He re-emerged in 2007 as a special adviser to then education secretary Michael Gove, who turned out to be something of a kindred spirit. The pair would rail against what they called “the blob” – the informal alliance of senior civil servants and teachers’ unions that sought, in his opinion, to frustrate his attempts at reform.
He left of his own accord to set up a free school, having rubbed a number of people in the ministry and in the Conservative Party up the wrong way.
He once described Brexit Secretary David Davis as “thick as mince” and as “lazy as a toad” and so irritated David Cameron the former prime minister called him a “career psychopath”.
His appointment as head of the Vote Leave campaign – dramatised last year in Channel 4 drama Brexit; The Uncivil War – was seen as a risk worth taking by those putting the campaign together but he left a controversial legacy.
Vote Leave was found to have broken electoral law over spending limits by the Electoral Commission and Mr Cummings was held in contempt of Parliament for failing to respond to a summons to appear before and give evidence to the Culture, Media and Sport Select Committee.
On the few occasions, he has been scrutinised by MPs, there have often been rhetorical fireworks and bad blood on both sides.
Mr Cummings, who is married to Spectator writer Mary Wakefield, has since criticised the failure of MPs to devise a plan for Brexit and believes the government should have waited longer to trigger Article 50.
He has hinted in blog posts he does not want to spend too long in his current role at No 10 but he has given no sign he is planning to leave any time soon.