Muslim born Tawfik Hamid - who has had close links with Al Qaeda's top brass and predicted the attacks on New York, Madrid and London - warned of worse to come in Britain.
And he called on the Government to act against the "cancer" of extremists hiding within the Muslim community.
The scholar, who has been forced to conceal his real identity after death threats from Islamic fundamentalists, says he was schooled in radicalism and indoctrinated into terrorism as a young man before escaping in the West.
Born in Egypt, he often prayed alongside Al Qaeda leaders including Osama Bin Laden's deputy Ayman Al Zawaheri.
He has now warned, "There will be future terror attacks in Britain and they will make the bombing in London look like nothing, I expect a major crisis in the next few years. I expect a major chemical attack on the water supply or on the food in Britain."
He said the failure of Western governments to act against the growing radicalism had allowed it to flourish. "This is like someone with cancer pretending they do not have it." They ignore it but will just grow and eventually it will kill them."
He said "I believe that the majority of the Muslim population are passive terrorists. The Western world classifies people into religious fanatics and moderates. We do not have moderates Muslims in the Muslim world. In Islam, the distinction is non religious or religious.
"Among the religious very few are active terrorists committing terrorist acts, but unfortunately the vast majority are passive terrorists. In their hearts and minds they support terrorist acts against the West and they have a symbolic relationship with the active terrorists.
"The Imams condemn terrorism and behave well in public to protect themselves from revenge attacks but they continue to preach what they really think in their mosques. The people who come in front of the media cameras and the government are the same people who are praying for Bin Laden in their mosques."
He added, "There will be no more than one per cent of Muslims who are active terrorists, but that is still a huge number of people. Western governments will not be able to solve this on their own. They will fail because they cannot understand the mentality behind extremism.
"There is no use in giving concessions. The more you concede, the more generous you are, the more it is seen as weakness and they will attack you again to get more concessions. The UK has been harboring barbarians and allowing them to speak out in public. The problem needs to be solved from within by reformists as well as without."
Hamid has first hand experience of Al Qaeda's fundamentalist teachings, having prayed alongside Bin Laden's right hand man for a year after he joined Jamaha Islameia group run by Al Zawahari in Cairo.
He also met with Sheikh Yusyf Al Qaradawi, who faced protests when he visited London at the invitation of Mayor Livingstone after supporting Palestinian Suicide bombers in Israel.
He said: Violence is a fundamental part of Islamic teaching. In Islam the books themselves preach violence against non Muslims. It is an idealogical war against the West to force you into subjugation before Islam. We live in the dark ages.
"They brainwash you the moment you enter the mosque as a child. Every Muslim child is brought up with idea that followers of Islam are superior, of Islam conquering the world."
"It is easy to say Islam is the religion of peace, but the reality is actually the opposite. For the majority of Muslims every terrorist act is a small victory against the West. They dream about being victorious against the infidels. So they become silent and that silence means approval. Unfortunately, such hatred of non Muslims is generated by the Islamic religion itself against those who do not follow it, irrespective of their deeds."
And he added "The only way to make Muslims satisfied with the West is for Westerners to submit to an Islamic or Taliban like system, stop their freedom and suppress women."