Profile: Abu Qatada
Radical cleric Abu Qatada has been described as a "truly dangerous individual" and a "key UK figure" in al-Qaeda related terror activity.
The Palestinian-Jordanian, whose real name is Omar Othman, has for seven years been fighting deportation to Jordan.
His defeat at the Special Immigration Appeals Commission (Siac) in February 2007 had represented a major victory for the government's strategy of finding ways to deport terrorism suspects whom it said could not be tried in the UK.
But Abu Qatada appealed on grounds that evidence extracted through torture would be used against him in Jordan, where he faces a retrial for plotting bomb attacks.
In January 2012 the European Court of Human Rights partly ruled in his favour, prompting his release from jail, albeit on strict bail conditions. It left ministers seeking further guarantees to enable them to continue deportation proceedings. The government secured an assurance from Jordan that the preacher would get a fair trial - and he was detained again.
But he has now been released on bail after winning a further deportation appeal to Siac.
Chairman Mr Justice Mitting ruled he was not satisfied Abu Qatada would be tried fairly.
Judges say there is a real risk that the preacher's retrial in Jordan would be unfair because it would include incriminating statements made by men who were tortured by the secret police.
The scholar, now 51, arrived in the UK in September 1993 and claimed asylum, saying that he had been tortured in Jordan. He had been living in Pakistan near the Afghan border shortly before his arrival in the UK.
In 1994 he was recognised as a refugee and allowed to remain.Islamist scene
He was among a large group of Islamists who sought refuge in the UK during the late 1980s and 1990s as they fled from despotic Arab regimes which they were seeking to overthrow.
End Quote Mr Justice Ouseley, 2007
In short, his views are to be found linked to many terrorist groups and their actions, providing the religious cover they seek; he propagates radicalising views, and his fund-raising is aimed at advancing the Islamist extremist cause”
Abu Qatada became an important player in the London Islamist scene - later dubbed "Londonistan" by its opponents - because of his credentials as a scholar.
During his early years in London, Abu Qatada preached at the Fourth Feathers community centre near Regent's Park and held meetings in his own home.
He was part of a broad movement that advocated imposing Islamic government on Muslim lands. He said that Islamic law justified taking up arms against despots and foreign invaders because they were the enemies of Muslims.
These ideas, developed over many years by hardline scholars, were part of the ideological roots adopted by al-Qaeda's to claim religious justification for its violence.
As the UK's security agencies tried to make sense of the Islamist scene, MI5 approached Abu Qatada on more than one occasion to ask for his help in minimising the threat to the UK.
By 1995, it was clear that Abu Qatada's influence was broad, particularly among Algerian and Egyptian armed Islamists. His religious rulings were taken very seriously by those who followed him.
In one religious opinion that year, he said it was Islamically lawful to kill the wives and children of "apostates" - those who have rejected Islam - in order to stop oppression in Algeria.
The practical effect was that armed Islamists in the country used his ruling to justify their attacks against civilians on the basis that anyone who wasn't with them was against them.'Views hardening'
Even as late as 1997, he was not considered to be fully part of the wider movement of international violent jihad, which al-Qaeda was coming to spearhead.
But the authorities believe his views were hardening, particularly after a sermon targeting Jews. And by 2001, the cleric had issued rulings justifying suicide attacks, as seen in a BBC Panorama interview the same year.
A Spanish judge, Baltasar Garzon, described Abu Qatada as the "spiritual head of the mujahedin in Britain" - so the question for the British authorities was whether Abu Qatada now supported "martyrdom operations" against Western targets.
The Security Service and police eventually concluded that Abu Qatada was a threat. In a court statement they said he was providing advice which gave religious legitimacy to those "who wish to further the aims of extreme Islamism and to engage in terrorist attacks, including suicide bombings".
The authorities said that a number of people arrested in connection with terrorism had described Abu Qatada's influence. Richard Reid, the would-be mid-Atlantic shoe bomber, and Zacarias Moussaoui, both jailed for involvement in terrorism, are said to have sought religious advice from him. The cleric's sermons were found in a Hamburg flat used by some of those involved in 9/11.
When Abu Qatada was questioned in 2001 over his alleged connections to a German cell, police found £170,000 cash in his home, including £805 in an envelope labelled "For the mujahideen in Chechnya". No charges were brought.
But on the eve of a new law enabling the authorities to hold foreign terrorism suspects without charge or trial, he disappeared. He was later tracked down to a council house in south London and taken to Belmarsh Prison.
The Law Lords eventually ruled such detention illegal and Abu Qatada was among those subjected to a control order, a form of house-arrest.
He was then rearrested and told he would be deported to Jordan, where he had been convicted in his absence of alleged involvement in a plot to target Americans and Israeli tourists during the country's millennium celebrations.Attitudes today
What is not publicly clear is exactly where he now stands. Some influential Islamists have in recent years rejected al-Qaeda - in particular Libya's largest jihadist group.
In December 2005, Abu Qatada made a video appeal to the kidnappers of British peace activist Norman Kember in Iraq. That recording, made inside Full Sutton prison near York where he was awaiting extradition proceedings, was broadcast in the Middle East. The question was whether this appeal was genuine, or simply tactical.
In 2008 he was briefly allowed out of prison on bail, while continuing his deportation legal battle. Mohamed Ali, who runs the Islam Channel on satellite television, has known the cleric for years and held talks with him during that period out of prison.
He told the BBC: "Abu Qatada has no links with terrorism [or] al-Qaeda and he never ever agreed or endorsed what was done in 9/11 in America or 7/7 in the UK.
"He said that if he had known that something was going to happen, he would lock them up. He thinks that jihad is limited to either defending Muslim lands when invaders come to Muslim lands or if force is being used to overthrow dictatorship regimes.
End Quote Bob Quick Former Scotland Yard anti-terror chief
To suggest that he couldn't operate and pick up contacts and reposition himself in the future is probably a bold assumption”
"He believes that the covenant between any Muslim coming to this country and the government stands and it should be honoured by both parties."
But Bob Quick, former head of counter-terrorism at Scotland Yard, doesn't buy this argument.
He said: "I would describe Abu Qatada as very dangerous, a man with significant influence, significantly well networked in Europe and the Middle East with very extreme views and prepared to promulgate those views and influence the views of others and their conduct.
"He was very well networked, very well connected, with al-Qaeda. He was an active supporter of terrorism and extreme Islamist objectives through terrorism.
"It might be dangerous at this stage to suggest his influence has waned.
"It may have waned because he's been in custody, mostly, for the last few years but to suggest that he couldn't operate and pick up contacts and reposition himself in the future is probably a bold assumption."
Such views are the reason successive governments have pursued Abu Qatada's deportation so doggedly.