I expected Hizb ut-Tahrir to be highly secretive and closed. But after a month of negotiations, the leadership committee decided to grant me exclusive access to the organisation's inner sanctum. I was going to be allowed to sit in on one of their indoctrination cells, or "study circles" as they call them.
Guided by an experienced cell mentor, new recruits would study the organisation's ideology for two years before being given full membership. These were the cells that US think-tanks such as the Nixon Centre and the Heritage Foundation had accused of churning out some of the world's most wanted terrorists and ideologues.
Zeyno Baran, the Nixon Centre's director of International Security and Energy Programmes, had given me a warning before I attended. "Hizb produces thousands of manipulated brains, which then 'graduate' from Hizb and become members of groups like al-Qa'ida," she said. "Even if Hizb does not itself engage in terrorist acts, because of the ideology it provides, it acts like a conveyor belt for terrorists."
At a hotel just five minutes from Heathrow's Terminal One, on a Sunday afternoon, I met members of one of Hizb's many London cells. Around a coffee table sat four thirty-something university graduates with good jobs and families. The group's mentor was Sajjad Khan, a middle-aged accountant. These were not the same angry and disenfranchised youths of the explicitly violent breakaway group al-Muhajiroun.
For three hours they sat discussing the intricacies of Marxist economic thought with not a mention of jihad, retribution or the glory of 9/11. It was the kind of enthused debate any university professor would have loved. So when even the Home Office agrees that the group is ostensibly non-violent, why does Downing Street want to see it proscribed, a move that would rank Hizb among the likes of al-Qa'ida and Hamas?
It would be foolish to think that because Hizb is non-violent it doesn't represent a threat to society. Critics of the group, and even former members, have repeatedly said that it is a threat to the cohesiveness of a multicultural society.
For example, in the recent general election Hizb told its members and the wider Muslim community not to vote as they would be participating in a society run by kaffirs or non-believers.
"What it preaches is quite an isolationary role for young British Muslims," a former member told me.
"I think its actions reinforce this idea that Muslims need to be separate and they shouldn't be at one with the wider community and the Muslim community." These anti-integration messages have, until recently, been combined with anti-Semitism. It is for this reason the group was banned in Germany in 2003 and the leader of the Danish branch given a 60-day suspended sentence in 2002.
This anti-integration message has been potent. More so because it has been left largely unchallenged by the Muslim community. For example, its last conference in Birmingham in 2003, entitled "British or Muslim", attracted 8,000 people. Its 2002 conference has been the biggest Islamic event in the UK to date.
There is a second danger Hizb poses. According to Ms Baran, it acts as a conveyor-belt for terrorist organisations. "The West can no longer ignore the deadly impact of Hizb ideology," she said. "It provides very simple answers to complex problems and reaches millions of Muslims through cyberspace, leaflets and secret teaching centres. It is time to name the war correctly: this is a war of ideologies, and terrorist acts are the tip of the iceberg."
There are a few examples of the conveyor belt in action in Britain. Omar Sharif, from Derby, tried to blow himself up outside a Tel Aviv nightclub in 2002. When MI5 searched his home they found plenty of Hizb literature. Sharif had also been leafleting for al-Muhajiroun in Derby only a few weeks earlier.
Omar Bakri, the head of al-Muhajiroun, led Hizb in the mid-1980s. He first brought it to national prominence after he called for the head of John Major during the 1990-91 Gulf War. "Major is a legitimate target," he told the Daily Star. "If anyone gets the opportunity to assassinate him, I don't think they should save it." Those remarks got him detained for 48 hours.
After this episode it is thought Hizb's central leadership, based in Jordan, decided to change the British branch's image so that it could appear as the mainstream voice of the Muslim community. Bakri left to set up al-Muhajiroun, but he took the same literature and reading material. Only the strategy - one of explicit violence and jihad - was to be different.
The London branch has now become a major support outpost for a vast global network of radical Islamic thought. Hizb's headquarters in Gloucester Road, London, produces literature to be distributed from Manchester to Malaysia and hosts the organisation's websites from around the world.
So should it be banned? There is a feeling within the Muslim community that if Hizb is banned, it will make the problem far worse. Dilwar Hussain, a research fellow at the Islamic Foundation in Leicester, said Hizb would become even more illicit in the eyes of the people it is trying to recruit - giving status to the ideology of resentment.
He also says that banning the group will drive Hizb underground: "Driving any group underground ... will disconnect that debate from the wider community and risk radicalising it even further," he said. "What should happen is that mainstream Muslim groups should be empowered to debate with them and tackle them head on." This hits the nail on the head. The problem with Hizb and al-Muhajiroun is that their ideas of anti-integration and global Islamism have been left unchallenged for almost 20 years. Banning the groups will ensure their ideas remain unchallenged.
If this is a battle of ideas, as Mr Blair has suggested, then using the law to suppress those non-violent expressions of thought will only serve to justify them further.
THE COST OF TERROR
Whitewater rafting course in North Wales where the alleged terrorists "bonded" before 7 July bombings.
Transport costs for four alleged bombers on 7 July including hire car, parking, return train tickets from Luton and four travelcards.
The cost of four medical cool-boxes and four large rucksacks to store explosives on 7 July.
Cost of the raw materials for around 50kg of explosive, the amount used on 7 July.
Cost of a commercial fridge to keep the explosives stable before the first bombing.
Government compensation to families for each dead victim.
Housing benefits claimed by Stockwell 21 July bombing suspect Yasin Hassan Omar.
Amount donated to London Bombings Relief Charitable Fund by Stagecoach, operators of the No 30 bus.
Compensation allegedly offered to the parents of Brazilian Jean Charles de Menezes, shot eight times by police on 22 July.
Amount raised so far by the London Bombings Relief Charitable Fund.
Money lost in hotel bookings in comparison with last year.
Lost ticket sales on the London Underground.
Losses reported by London restaurants.
The amount spent on extra policing for the capital.
Money lost from London tourism.
Money lost from UK tourism in the three-week period after the bombings.
Lost revenue recorded from central London retailers.Reuse content