Mahmoud Othman, aka Abu Omar, aka Abu Qatada, is finally standing trial in Jordan for terrorism. But Abu Qatada has much more blood on his hands than the cases before the state security court in Amman. Britain's decade-long refusal to deport him, finally resolved last year, allowed him to continue his more sinister work as one of Osama bin Laden's key operatives in Europe.

If he had been deported from Britain in 1998 or 1999 when Jordan first asked, 9/11 might never have happened. Britain's refusal to allow him to be brought to timely justice was one of the most spectacular failures of Her Majesty's Foreign Office.

Abu Qatada was born in Bethlehem in 1960. He was convicted in absentia by the Jordanian State Security Court in 1998 for his involvement in a series of explosions in Amman at the Modern American School and in the car park of the Jerusalem Hotel in May 1998. He was absent from court because he was in the U.K. and the British government refused to extradite him.

Both bombs were small molotov cocktails and no one was hurt. Several cars belonging to former Jordanian government officials were also set alight.

Jordanian security services intercepted phone calls and monitored members of the group who became known as the "Afghan Arabs." They zeroed in on Abu Qatada who was believed to be funding and directing their activities through an Al-Qaida group known as Islah Wahadi.

In 2000, he was convicted to death in absentia for his role in funding a terrorist cell arrested in December 1999 in Jordan. This 15-strong group was convicted of planning a series of bomb and poison gas attacks over the millennium celebrations – almost a dress rehearsal for the 9/11 attacks in New York and Washington, but not widely reported at the time.

Jordan had again requested that the British Government extradite Abu Omar to Jordan in December 1999. Christopher Battiscombe, British Ambassador to Amman, said at the time Britain was trying to be "helpful" in responding to the Jordanian request but nothing was done.

When British Foreign Secretary Robin Cook went to Jordan in 2000, the visit almost collapsed because of Britain's refusal to extradite him.

Jordanian officials believe Abu Omar was bin Laden's bookkeeper and treasurer in Europe. They say he was connnected to several of the September 11 hijackers and had close ties to Mohammed Atta and the other two hijackers from Hamburg.

"We believe he is the central figure in the Al-Qaida network in Europe," Samih Buttikhi, the director of the Jordanian intelligence service (Mukhabarat) at the time of the arrests and the king's top security adviser, told me in late 2001. "I am very angry that he is still at large. There is no lack of information – from Jordan, France, Spain and Britain – about his involvement in financing Al-Qaida's terrorist operations. We have evidence of the money transfers from London. He was guiding the group in Jordan where to strike and organizing ideological indoctrination, terrorist training and finance."

"There is no doubt in anyone's mind in the security services throughout Europe and the Middle East that he is an active terrorist linked to Al-Qaida," he said.

Buttikhi charged that British laxity before 9/11 had enabled Abu Qatada to carry on his terrorist activities unhindered.

"Jordan was warning about the cancer of Al-Qaida for years and no-one listened," Buttikhi told me at his plush and closely-guarded home in the Jordanian capital Amman shortly after the 9/11 attacks.

"We enjoyed close co-operation on a professional level with the security services of Britain, the United States and other European and Middle East countries, but we had problems when the decisions reached the political level. The politicians didn't want to take the tough measures necessary to deal with these people," he said.

"The failure was not primarily a failure of the security bodies," he said. "I blame those who tied their hands and put bureacratic obstacles and laws in their path which in the end failed to protect anyone. The slogan of human rights in Europe in particular went much too far and failed to protect the human rights of ordinary people against terrorism."

"After we exposed and foiled the Millennium plot in Jordan, foreign security organizations took the threat seriously but the decision-makers failed to take the proper measures," he said. "If only they had listened to us, then the 9/11 attacks could well have been prevented. The Western politicians simply did not believe anyone could be capable of such terrible crimes, but we are Arabs and we understand the Arab mentality. I wish they had listened."

"The British have to reconsider their legislation in the light of global terror," he warned me at the time. "Abu Qatada and others enjoyed British protection from Jordanian justice when they should simply have put him on a plane and sent him. The same goes for other terrorists sentenced in their countries."

The millennium plot first came to light when the U.S. State Department issued a travel warning on December 11, 1999 warning Americans about possible millennium terror attacks and the Foreign Office followed suit shortly afterwards.

An FBI report in December 1999 said the Jordanian cell was linked to Osama Bin Laden and was planning "five to 15 operations" in the Middle East and elsewhere using explosives and poison, including gas grenades.

Jordanian officials said the group was planning terror attacks on tourist sites, Israeli and U.S. targets during the millennium celebrations.

The Jordanian cell members were arrested in early December 1999 as they returned from Afghanistan where they had received military training in Bin Laden's camps. They were carrying false passports.

The suspected leader of the cell was Khalil Deek, a Jordanian-American who was extradited from Pakistan to Jordan on 16 Dec 1999 after being arrested at his home in Peshawar on the Afghan-Pakistan border.

Deek was also suspected of leading a terror cell based in California which planned several operations in the early 1990s but were never carried out.

He was believed to be a close lieutenant of bin Laden and met frequently with Bin Laden in Afghanistan.

15 members of the cell went on trial in Jordan in April 2000, where prosecutors linked them to bin Laden's Al-Qaida organization. Most were found guilty and sentenced to various terms of imprisonment.

Perhaps, finally, after years of British dithering, Abu Qatada will get the prison cell he deserves. A shame it didn't happen earlier. There might have been no 9/11.