'I'm satisfied that there is every likelihood that this plot would have succeeded but for the intervention of the police and the security service,' the judge said.

'Had this conspiracy not been interrupted, a massive loss of life would almost certainly have resulted - and if the detonation was over land, the number of victims would have been even greater still.'

The judge said that the plot had 'reached an advanced stage in its development', with the men in possession of enough chemicals to produce 20 detonators aimed at blowing up flights from Heathrow airport to San Francisco, Washington, New York, Chicago, Toronto and Montreal.

The men's arrests in August 2006 caused chaos to the global aviation industry and led to a strict security check regime - with a 100 ml limit on the amount of liquids passengers can carry - that continues to this day.