Midway through Awaken!! – David Icke’s marathon Wembley Arena show – two men are outside, smoking. “Another four hours, innit?” sighs one. His friend sighs back, “He’s very open-minded, isn’t he?”

The man who bills himself as “the world’s biggest maverick and unique freethinker” has the stamina of Fidel Castro. Notwithstanding breaks and musical interludes, Icke’s last ever big UK event is, in essence, a day-long lecture to “join the dots” and show “how deep the rabbit hole goes”.

In pink shirt and black slacks, the 62-year-old paces the stage for hours with help from hundreds of slides but no notes or refreshments. Chummy rather than shrill, he deploys jokes, PG-rated profanity (“fricking”) and crowd-pleasing digs at his detractors.

Icke’s mission to promote “infinite consciousness” started badly when the former BBC Grandstand presenter called a press conference in 1991 and described himself as a “son of the Godhead”. When asked subsequently on Terry Wogan’s chat show if he was claiming to be the Son of God, he did not disagree. Intense public derision followed but Icke has since become a prolific author, lecturer and anti-hero of alternative media.

During that period, the world has become increasingly Icke-friendly. Like the Icke admirer Russell Brand, he appeals to those who have lost faith in politics and the mainstream media and are hungry for counter-narratives. Everything from the financial crisis to rumours of a Westminster paedophile ring wins him new followers.

From what I can see, Icke’s fan base is diverse, friendly and overwhelmingly normal-seeming. “I’m surprised there aren’t more people wearing tie-dyed clothes,” says Rupert, a Londoner who has worked with Icke. “Everyone looks well dressed and quite well-off.”

“Some people would expect tinfoil-hat conspiracy theorists but they’re not at all,” agrees Paula, a middle-aged woman who discovered Icke two years ago. “I was Labour, very left. Not any more. My eyes opened to a whole different world.”

Icke plays a numbers game, covering so much ground that nobody could agree with all of it but everyone can find something. On the subject of bankers, Gaza or austerity, he uses the language of the left; turning to man-made climate change or “the centralised fascist-communist bureaucratic dictatorship of the EU”, he speaks fluent Ukip. He appeals to New Age health buffs with attacks on vaccines and the food giant Monsanto; and to conspiracy theorists with hypotheses about 9/11. “People say I see conspiracies everywhere,” he says. “I don’t. I see one conspiracy that takes different forms.”

The latest iteration of Icke’s meta-narrative involves the Archons, an ancient race of reptilian psychopaths who have hijacked our perception of reality in the manner of the film The Matrix. The Archons have blinded humans to the real world, which resembles that in Avatar, and are creating a dystopian society, à la The Hunger Games. This inverted reality is being broadcast from Saturn via the Moon, which is hollow.

Some might consider the Archon business fatal to Icke’s credibility but his fans happily compartmentalise. “It’s not about our differences,” says a man calling himself Mr SiNX. “He can get people from different ideologies to look at the similarities.”

Icke is hard to pin down. His obsession with the Rothschilds suggests a possible coded anti-Semitism but then he also blames Al Gore, Bill Gates, Jimmy Savile, Google, the UN, the BBC and the Queen. He perceives Saturn’s iconography in Katy Perry videos, Monsters, Inc, the hand gestures of Jay-Z and Angela Merkel and Father Christmas. “Santa is an anagram of Satan,” he explains.

Nobody claps that bit but the applause steadily mounts throughout the day. During the climactic section, he closes his eyes, extends his arms and chokes up a little while clicking through well-known quotations illustrated in the style of inspirational Facebook infographics. Although Icke dislikes religion, his meta-narrative is basically religion without God: the Archons can be defeated by peace, love and a “revolution” in consciousness. It’s an attractively simple conclusion and the crowd roars.

It is striking how few people leave early. As the ranks of the politically disaffected grow, so, too, will his constituency. “It’s been very interesting,” reflects Lucy, a student from Bath. “I don’t assign myself to any group or party. I see myself as an individual thinker.”

Towards the end, Icke surveys his tribe with pleasure. “They told me 25 years ago, ‘You’re finished. You can’t go any further after all that ridicule.’” He smiles and raises his arms. “Watch me.”