When Dominic Cummings found out he was to be the central character in a high-profile TV thriller about the Brexit campaign, he was suspicious. James Graham, the playwright behind the Channel 4 drama, said he “understandably had to persuade him it wasn’t a stitch-up job.”

Others might have been delighted to be played by Benedict Cumberbatch. But then, Cummings has always followed his own path. Graham chose the man seen as the mastermind of the Vote Leave campaign as the central character in his drama about the referendum because, he said at a screening this week, “he is different, and different is fun … He doesn’t speak or talk or behave like other political strategists I have met.”

Brexit: The Uncivil War, which is to air on Channel 4 on Monday night, shows Cummings as he and his team build the campaign that dismayed the political establishment. His reticence about being portrayed is seen by some as evidence of why he is so interesting.

He is the opposite of the egotistical politico cliche, argues Prof Tim Bale, the author of a modern history of the Conservative party. “This is someone who really believes in what he believes in,” he said. “He believes that what he wants to do will actually improve society. He’s in it for that, rather than any glory or status.”

And yet, at the same time, many observers see a lust for recognition in Cummings’ behaviour. He has hardly shied from controversy over the course of his career. He has derided Westminster figures in eye-catching media interviews and published rambling blogposts that are obsessed over by Westminster insiders. In July 2017, the former adviser to Michael Gove tweeted that the then Brexit secretary, David Davis, was as “thick as mince”, as “lazy as a toad” and as “vain as Narcissus”.

He has variously been described by people who know him as mad, eccentric and brilliant. He is known for his comparatively scruffy appearance – it is apparently not unusual for him to be seen wearing a jumper inside out – and his sharp tongue.

And yet others see an overrated political operative and nothing more. The conundrum that fixated so many of his allies and opponents is summarised in the film by Rory Kinnear, playing his opposite number in the remain campaign, Craig Oliver: “He’s not the Messiah. He’s just a fucking arsehole.”

None of this bothers Cummings. “I don’t think he minds a lot of the stuff that is said about him,” one friend said. “Because in a weird way, it’s not unhelpful if people think you’re an evil genius.”

Cummings, the son of an oil rig project manager and a special needs teacher, was born in Durham in 1971. He attended a state primary school followed by the fee-paying Durham School and, in 1994, Oxford University, where he studied ancient and modern history.

After three years living in Russia, where he attempted to set up an airline connecting Samara in the south with Vienna, the then 28-year-old Cummings became campaign director of Business for Sterling, which worked to prevent Britain from joining the euro.

Although he has never, as far as anyone knows, been a member of a political party – he said in 2014 that he saw them more as “vehicles of convenience” – Cummings was headhunted to be director of strategy for the then Tory leader, Iain Duncan Smith, in 2002, following a second easy victory by Labour in the 2001 general election.

While he was seen as a “young, thrusting moderniser”, according to Bale, Cummings quickly offended party traditionalists. On one notable occasion, he argued the Conservatives should not attempt to lead the campaign against British adoption of the euro, because “just about the only thing less popular than the euro is the Tory party”. He quit the job after only eight months, describing Duncan Smith as incompetent.

Dominic Cummings in 2001, when he was campaign director at Business for Sterling, which worked to prevent Britain joining the euro. Photograph: David Levenson/Getty Images

Following the 2010 general election, the then education secretary, Michael Gove, appointed Cummings as his chief of staff – an appointment that was initially blocked by David Cameron’s then director of communications, Andy Coulson, until his resignation.

Many in Whitehall found Cummings as difficult as he found them. In 2013, civil servants in the Department for Education complained to the Independent of an “us-and-them, aggressive, intimidating culture” created by Cummings and Gove. In an internal grievance report, the events surrounding the attempted removal of a senior civil servant were described as being reminiscent of an episode of The Thick of It.

He never hid his disdain for the workings of Whitehall and the Palace of Westminster. In 2014, after leaving the DfE, Cummings told the Times: “Everyone thinks there’s some moment, like in a James Bond movie, where you open the door and that’s where the really good people are, but there is no door.”

In the same interview, he let loose on Cameron, describing the prime minister as “a sphinx without a riddle”, and Cameron’s chief of staff, Ed Llewellyn, as a “classic third-rate, suck-up-kick-down sycophant”. The remark prompted a thinly veiled retaliation from the then prime minister, who told an audience a few days later that there seemed to be a path from special adviser to “career psychopath”.

Cummings similarly lashed out at the Liberal Democrats, using his blog to accuse the Tories’ coalition partners of “stupid gimmicks”. The then deputy prime minister, Nick Clegg, responded by telling broadcasters that Cummings was “a rather peculiar former Conservative adviser” who had allowed his former role to go to his head.

In 2015, Cummings and the political strategist Matthew Elliott founded Vote Leave, which was designated by the Electoral Commission as the official EU referendum leave campaign in April of the following year.

Speaking to Newsnight in July 2016, Elliott described the “genius moment” that Cummings came up with the campaign’s slogan. “The message has to be ‘vote leave, take control’,” Cummings reportedly said. “And that developed into ‘vote leave, take back control’,” said Elliott. The message stuck. In a TV debate in June 2016, Boris Johnson used the phrase “take control” seven times in his one-minute opening statement.

The former Labour MP Gisela Stuart, who became chairman of the Vote Leave campaign in March 2016, said despite differing from him in many areas of politics, she liked Cummings. “I liked working with him because he makes up his mind about what he wants to do and then focuses quite strategically and relentlessly on what needs to be done in order to achieve it,” she said.

Since the campaign’s success, its tactics have been the subject of a series of high-profile scandals. Vote Leave’s use of data analytics has been scrutinised after the Observer reported that the controversial data-mining company Cambridge Analytica had links to the Canadian digital firm AggregateIQ, on which Vote Leave spent 40% of its campaign budget.

In July 2018, the Electoral Commission announced Vote Leave had been found guilty of breaking electoral law by overspending, following testimony from whistleblowers. The group was fined £61,000 and referred to the police.

Cummings has used his blog to furiously defend himself and the Vote Leave campaign in the face of the allegations. “Hardcore remainers are similar,” he wrote in July last year. “They want a second referendum and this requires delegitimising the first. They therefore hysterically spread false memes while shouting ‘liars’ at leavers.”

While Cummings has not given any media interviews since the referendum, he told the Guardian he had not seen the film and had nothing to say about it. But his family seem content with Cumberbatch’s performance. Writing in the Spectator last month, his wife, Mary Wakefield, detailed an evening in the summer of 2018 when Cumberbatch came round for a dinner of “vegan pie”.

She spoke of the relief that he had not come to judge her husband but “to become him”. “He looks so like him in the trailer,” she said. “His mannerisms are so perfect that it’s hard not to imagine he’s having Dom-ish thoughts.”