Sheikh Omar Bakri Mohammed is an affable man with a benign smile and a penchant for chuckling. He uses his soft, rather feminine hands to emphasise the eminent reasonableness of his arguments and, sitting in his office, surrounded by awed supporters, munching on bags of crisps, he presents a contented, even jovial figure.
In an instant, the mask slips. "Don't make me look like a Jew!" he barks at a photographer about to take his picture.
"Sheikh" Omar readily casts aside his amiable persona when he deals with the issues that have made him notorious. Indeed, only a few minutes in his presence reveal a wellspring of hatred.
"People say that I am a racist because of some of the things I have said about Jews in Israel," he said. "That's nonsense. I am not against the Jews, I am simply against the state of Israel. The state of Israel, I believe, is a cancer which must be removed.
"We challenge the truth of the Holocaust but we challenge it from an academic perspective. We believe it has been certainly exaggerated to justify the occupation of Palestine. I also believe that the Israelis and the Nazis are one and the same in their refusal to accept the sanctity of life."
Holding court in his shabby north London office, preparing to receive visitors such as Abu Hamza - the Muslim cleric who last week warned or "terrorist reprisals" in Britain - he oozes animosity towards the hated "Zionists".
Literature distributed by his group, Al-Muhajiroun, is even more explicit.
"Oh Jew, hide in your bunkers because the Mujahideen are coming so be ready to surrender or die like the dog," one leaflet reads.
Another, titled The Seven Deadly Sins, rails against homosexuality, lesbianism, adultery and fornication. The group calls for the "severe punishment for the perpetrators of such crimes against humanity".
These are not aberrations. They are declarations of policy.
Just three months ago, the group distributed a leaflet entitled, "Israel, the cancer that must be removed". It concluded: "The Mujahideen are the tools which will surgically remove the cancer of the state of Israel."
One pamphlet, popular with the group's young fanatics, makes clear the belief that attacks on Jews are essential. It says: "The hour will not come until Muslims fight the Jews and kill them."
Omar, 44, has studied carefully the limits to which British law can be pushed, and senior Scotland Yard sources say he stops short of saying or doing anything that could lead to a criminal charge.
His outbursts dismay and outrage many but, police say, he knows precisely where to stop to avoid legal action.
He is a highly intelligent and educated man, born in Aleppo, Syria. His father was a wealthy businessman who traded in livestock.
He claims to have 28 brothers and sisters but says many were killed by the country's late President Assad in his crackdown on Islam. Omar says he was always fascinated by the faith and took a degree in Islamic law at the University of Damascus. He claims he felt threatened by the political situation in Syria and fled to Britain as an asylum seeker in 1986.
He was already a fundamentalist. Within three months of his arrival, he was arrested as an organiser of a Muslim rally in London.
A year later, he was arrested again during protests against the controversial film The Last Temptation Of Christ. During his time in the Middle East, he was involved with the militant Islamist group Hizb ut-Tahrir and on arrival here he set up a UK branch with another activist Farid Kassim.
Together they built it into the most influential extremist Islamist group in the country. But after 10 years, the two men fell out and Omar began his own organisation, pronouncing himself spiritual leader and demanding the creation of Islamic republics throughout the West.
He claims to have between 6,500 and 7,000 members. He has also proclaimed himself to be "Judge" of the British Court of Shariah, which seeks to establish the dominance of Islamic law in this country and abroad.
He has never had a job, other than the promotion of his particular form of Islam. For a while he raised his six children in Edmonton on a mixture of donations and state benefits. But now he says the only state payment he receives is child benefit.
His members pay a proportion of
their incomes to Al- Muhajiroun and friendly businessmen make donations.
He doesn't need state money to survive, he says.