A Muslim group that wants to open a giant £100 million mosque in London has set its sights on “winning the whole of Britain to Islam”.

Tablighi Jamaat aims to build an Islamic complex near to the site of the 2012 Olympic stadium, with a mosque for 12,000 people, by far the largest religious building in Britain.

The organisation, which has millions of followers worldwide, insists that it is a peaceful, apolitical revivalist movement that promotes Islamic consciousness among individual Muslims. However, intelligence agencies have cautioned that the group’s ability to fire young men with a zeal for Islam acts as a staging post, for some, along a path that leads to jihadist terrorism.

Kafeel Ahmed, the Indian doctor who died from burns last month after trying to set off a car bomb at Glasgow Airport, is the latest in a line of terrorists for whose initial radicalisation Tablighi Jamaat has been blamed. The group (literally, the preaching party) belongs to the ultra-conservative Deobandi school of thought within Sunni Islam, whose adherents run more than 600 of Britain’s 1,350 mosques.

In recent days The Times has exposed the virulently anti-Western creed of some British Deobandis who preach that non-Muslims are an evil and corrupting influence. Their defensive, isolationist approach to life in Britain is shared by many British supporters of Tablighi Jamaat.

One leading advocate, Ebrahim Rangooni, has said that the movement seeks to “rescue the ummah [the global Muslim community] from the culture and civilisation of the Jews, the Christians and [other] enemies of Islam”. Its aim, he wrote, is to “create such hatred for their ways as human beings have for urine and excreta”.

Mr Rangooni has also given warning to parents that non-Muslim schools “turn humans into animals” and that sending a Muslim child to a British college “is as dangerous as throwing them into hell with your own hands”.

Representatives of Tablighi Jamaat refused to attend a public meeting on Friday to discuss plans for the “mega mosque” in West Ham, even though the debate was organised by a Muslim group.

Tablighi Jamaat was founded in 1926, in India, by a Deobandi scholar, Muhammad Ilyas, who wanted to raise Islamic awareness among rural Muslims in south Asia. He promised them that by obeying Islamic laws and following the example of the Prophet Muhammad in their personal lives they would one day “dominate over non-believers” and become “masters of everything on this earth”.

Ishaq Patel, Tablighi Jamaat’s first amir (leader) in Britain, is said to have been on pilgrimage in Mecca when Ilyas’s successor gave him a long-term mission to win “the whole of Britain to Islam”.

Yoginder Sikand, a Muslim expert on the movement, says that its ethos of “social and cultural separatism and insularity” seeks “to minimise contacts with people of other faiths”.

The self-segregation that this encourages is evident in Dewsbury, West Yorkshire, where the group has its European headquarters. The Tablighi Jamaat complex – housing its large Markazi mosque and a Deobandi seminary called the Islamic Institute of Education - is based in the Savile Town area, which has an 88 per cent Asian population. The overwhelming majority of its 5,000 residents are Muslims from Pakistan or the Gujarat region of India and some, at home and at work, have little contact with nonMuslims.

It was on the advice of a Tablighi Jamaat scholar that Aishah Azmi, a Dewsbury teaching assistant, refused to remove her full-face veil in the class-room while helping young children who were learning to speak English.

Mr Sikand says: “There is little doubt that the sense of cultural separatism and heightened [Islamic] identity consciousness fostered by Tablighi Jamaat can be taken advantage of by more assertive Islamist groups that have a more explicit political agenda.”

One of the suicide bombers who attacked London in July 2005, Shehzad Tanweer, studied at the Deobandi seminary in Dewsbury and Mohammad Sidique Khan, the leader of the 7/7 terror plot, was a regular worshipper at the adjoining mosque. Richard Reid, the shoe bomber, was said to have been influenced by Tablighi Jamaat, several of whose adherents were also among those arrested last year over an alleged plot to blow up transatlantic airliners.

Shabbir Daji, a trustee and secretary of the Tablighi Jamaat mosque in Dewsbury, told The Times that the movement’s aim was “unity among all humanity”. He said that it had no hidden agenda. “We never come out on demonstrations against the Government,” he said. “Our aim is to make each and everyone . . . a better Muslim.”

More than 250,000 people have signed a Downing Street petition against the London mosque. Local opposition is being led by Alan Craig, a Christian Peoples Alliance member of Newham council. He accuses Tablight Jamaat of being “a separatist sect that preaches a them-and-us approach to relations with the nonMuslim community” and encourages the creation of “Islamic enclaves” in Britain.

“There are many moderate Muslims who object to the teachings of Tablighi Jamaat. They know that it preaches hostility to non-Muslims. Some have friends and family members who have been radicalised by this movement.”

Irfan al Alawi, international director of the Centre for Islamic Pluralism, says the missionary work of Tablighi Jamaat acts as “a recruitment agency for jihad” in Afghanistan, the occupied territories and Iraq. “They go around deprived areas of British towns and cities, knocking on doors and urging young Muslims to come to their gatherings,” he said.

“The mega-mosque complex would become a flagship for Tablighi Jamaat’s mission to indoctrinate Muslims with a hatred of the West and the kuffar [non-Mulims].”

Tabligh Jamaat is expected to submit a formal planning application for the West Ham mosque before the end of the year.