Jet plot 'vindicates' UK security

The verdicts were a vindication of Britain's intelligence efforts, former security minister Tony McNulty said.

On Monday, Abdulla Ahmed AliAhmed Ali, 28, Tanvir HussainTanvir Hussain, 28, and Assad SarwarAssad Sarwar, 29, were convicted of conspiring to activate bombs disguised as drinks.

The convictions followed two trials and an operation which cost more than £35m and strained UK-US relations at times.

The arrests in August 2006 caused chaos to international aviation and prompted the current restrictions on liquids.

Wave of attacks

Security officials on both sides of the Atlantic believe the men wanted to kill thousands in the air and possibly more on the ground in a wave of attacks causing more devastation - and political fall-out - than the 11 September attacks.

It has emerged that the MI5 surveillance on the terror cell was being followed at the very top of American politics.

UK intelligence officers believed the plot - the biggest terror investigation in the UK - was directed by al-Qaeda figures in Pakistan.

The BBC understands that the key contact for the plotters was a British man, Rashid Rauf, now thought to be dead.

He was arrested in Pakistan in 2006, the BBC has been told, following a meeting at the White House chaired by President George BushGeorge Bush.

The president and his advisors were said to be so concerned about the threat to America they encouraged the Pakistanis to arrest Rauf. This has been denied by former advisors to President Bush.

The move caused intense annoyance to the British authorities running the surveillance operation of the suspects, as it meant they had to bring the operation forward in a hurry.

The Guardian newspaper said former US homeland security chief Michael ChertoffMichael Chertoff confirmed that the US administration had been on such a heightened state of alert about the plot that it turned back a plane in mid-air two days before the arrests of the plane plotters in the UK.

Scotland Yard's Counter Terrorism Command had what they say was "good coverage" of the suspects on that date and were waiting for more definite evidence before acting.

At the time of his arrest, plot ringleader Ahmed Ali had identified seven US and Canada-bound flights to blow up over the Atlantic within a two-and-a-half-hour period.

Mr McNulty told the BBC: "There were many straight after these arrests who were saying 'oh, it's just another attack on the Muslim communities, it's just another plot that will be seen to be not quite what the authorities are saying'."

The convictions were, he went on, "a real vindication of a lot of effort by a lot of people, security services, police, and equally the Crown Prosecution Service for having the courage to go back when the juries who were hung last time and say 'look, hold on, we think there is something here, we need to go further'."

Former Prime Minister Tony BlairTony Blair, who was leader at the time of the arrests, said the convictions were a tribute to "the professionalism, commitment and courage" of the police and security services.

Writing in the Sun newspaper he said: "These dedicated men and women work tirelessly behind the scenes, whose names we will often never know, unable to get the full, public credit they deserve.

"I know we are all safer because of their work."

Four other men were found not guilty of involvement in the suicide bomb plot.