"SEE that dirt up there? That's eggs, people throw them at my window," says David Icke matter-of-factly as we stand outside his Isle of Wight flat.

Walking round the corner towards the car park, he points to a number of deep scratches etched into the paintwork of his modest car.

"It's stuff like this. It's a lovely car; it goes brilliant so if it has a few scratches, sod it. But it does make you wonder.

"These are the people I am trying to alert to my plight. It's crazy but it's a small price to pay."

Life for Icke for almost 20 years has not been easy.

Turn the clock back to 1991 and you will probably remember that infamous Wogan interview, in which, dressed in a turquoise shell suit, he proclaimed himself to be "the Son of God".

Overnight he became Britain's most ridiculed man. Nutter, weirdo, freak, loony - he has been called them all. Icke was known at the time as a respected BBC sports reporter and as national spokesman for the Green Party.

It was an astonishing piece of television, as audiences - both in the studio and at home - watched open-mouthed as Icke destroyed his reputation in the space of one short interview.

Incredibly, he says he knew what he was doing.

He did not have a choice. He felt compelled to share his recent insight into the evil forces at work across the world and to warn people of what was coming.

Before our meeting I had read up on Icke's theories on the Internet. It is well-publicised, I learnt, that he believes that the world is ruled by a powerful elite called the Illuminati', a secret society made up of a race of reptilian humanoids.

He says that 13 bloodline families have this hybrid DNA and can shape-shift to disguise their true form.

Their descendants - which Icke claims include George Bush, Tony Blair, the late-Queen Mother and, randomly, country singers Kris Kristofferson and Boxcar Willie - practise Satanic worship, including blood-drinking and child-sacrifice.

Their aim, I read, is to take control of all aspects of society through a system of mind control.

It is only in the last few years that Icke himself admits that people have started listening.

The tide started turning after 9/11 and the invasion of Iraq, when many people became distrustful of their governments. According to Icke, people realised what he had been writing about for years, was happening - that they were being lied to by those in charge.

Today, his famous fans include Robbie Williams (they e-mail and speak on the phone) and Prince (who invited Icke to a concert last summer).

Inside his small flat in Ryde, we sit in his living room - the magnolia walls adorned with framed prints of steam trains and family photos lovingly displayed in every spare space.

Those familiar features are still there - not least those striking blue eyes - but his hair is now silver and he's not as svelte as he once was. Two decades have passed since his heyday after all.

But one thing that has not changed is his conviction. In fact it is stronger than ever.

Over the years he has honed his ideas - writing 16 books and working the lecture circuit - and become extremely well-versed in the mother of all conspiracy theories.

This is the man, after all, who is due to give a seven-hour lecture on his controversial beliefs at Brixton Academy in May (it sold-out three months in advance).

As we settle down for the interview, Icke - initially between mouthfuls of soup which is soon left to go cold - goes into full-blown lecture mode, barely once pausing for breath.

It is a three-hour long, intense experience that will ultimately leave me feeling like I have been run over by a steamroller.

Born on a council estate in Leicester, his family were "skint, I mean really skint", he tells me.

As a young boy he fell in love with the Island on rare summer holidays, he can still remember playing Isle of Wight ferries in his paddling pool. After realising a dream to move to the Island in 1982, the grandfather-of-two has been there ever since.

As my Dictaphone whirs between us, capturing his every word as he holds court, he - rather ironically - tells me how much he hates the limelight.

This from a man who has lurched from one high-profile job to another throughout his life.

As well as the politics and TV career, there was also a stint as a professional goalkeeper for Coventry City in his younger days and, of course, there's what he's doing now.

The 55-year-old doesn't seem like your average shrinking violet as he tells me, on more than one occasion, not to interrupt him or just carries on regardless when I ask a question in a vain attempt to break-up his longer soapbox-style speeches.

He would hate to hear it, but on frequent occasions he sounds remarkably like a politician, constantly dodging questions.

He has to stay in the public eye, Icke insists, to communicate the "suppressed information" he has uncovered. "I've spent 20 years full-time in what is now 45 countries researching this. When you know what I know as a result of that, and you know what the agenda is, you just can't walk away from it even if you want to."

Life, he declares, is like "a movie" as he sits forward in his chair, gesticulating wildly. "It is a version of events, that's all it is," he says. "Behind the movie, the real deal is going on.

"The greatest form of control is when you persuade people that they're free, while their lives are being fundamentally controlled.

In simple terms, you put them in a cell and make sure they can't see the bars."

When asked if he is referring to the reptilians, I get a very sharp response.

"No. I'm not talking about reptilian stuff because I only talk about that when there is a lot of time that can be given to it," he retorts with a loud clunk of his soup-spoon.

"It's like me, a few centuries ago, saying to you, the Earth's round it ain't flat, all right?

"You could go away and say (adopting a thick Midlands accent) he says the Earth is round it's not flat, he's mad because if it were round we'd fall off the bottom, ugh he's an idiot."

Reverting to his normal, more measured tones, he continues: "But if you brought into that, which was not known at the time, the law of gravity, suddenly what appeared to be ludicrous becomes, oh I can see how it's done now'.

"I'm a dot connector so I have to write about many subjects and connect them together. And you can only understand the reptilian side of this by doing that, so I don't talk about that in the media because it's a waste of time."

Adopting the silly voice again, he rants, "Oh, he says lizards run the world'."

Back to normal, he adds: "If people want to know about it they'll read my books. It's there in great length."

In 15 to 20 years we will all be living in a "global fascist state" he assures me. People should "just read Orwell's 1984" if they want to learn what the future holds. "But then add a bit more because it's actually more extreme than even he envisaged, but he was close."

The conversation continues with insights as diverse as that human microchipping will soon be widespread, that we're living in a "holographic version of the Internet" and that children are regularly being sacrificed on the Isle of Wight (and everywhere else for that matter) - it's a lot to take on board.

For Icke, his life changed forever after a string of bizarre experiences in the late 1980s when he persistently sensed a strange presence around him.

A visit to a hands-on-healer finally revealed what he had been searching for.

Recollecting the moment, he says: "I'm a national spokesman for the Green Party and I'm introducing the sport, and this thing is telling her that I'm going to go out on a world stage eventually and reveal great secrets that one man cannot change the world, but one man can communicate the message that can change the world. That there was a shadow across the world that had to be lifted, a story that had to be told and I was going to face enormous opposition doing it.

"They, whoever they are, I still don't know that, said they were always going to be there to protect me. I'm sitting there thinking you're having a laugh, but from that moment my life changed very quickly, very dramatically."

Before long, twice-married Icke got the call to appear on Wogan. By this stage the BBC had not renewed his contract and he was no longer with the Greens.

"They wanted to talk to me because I was in all the papers because this strange thing had happened," he says.

"I didn't care about the effect on my career because there was no career."

The fall-out from the infamous interview for his family was devastating.

"I couldn't walk down any street in Britain without being laughed at. My kids were ridiculed at school."

And while Icke claims he does not care, many people are still laughing.

If there is one thing that he does convince me of, it is his complete and utter confidence in his beliefs.

Incredibly articulate and fiercely intelligent, he is a man who remains on a mission to change the world.

"I'm 56 in a month, what have I got ten years, 20 years maybe?" he says. "I'm not doing this for me. I ain't going to have to live the rest of my life in an Orwellian nightmare.

"The children of today and the grandchildren of today are going to have to be living it. That's my motivation, that's what pushes me on.

"It may be bizarre but I want the people who abuse me to be free as well."

This is a man who remains convinced that we won't be laughing at him for much longer.