A British Islamic extremist who idolised Jihadi John has been jailed for life for planning a terror attack on American military personnel in Britain.

Delivery driver Junead Khan, 25, was a 'committed supporter' of Islamic State (IS) and plotted to kill a soldier using a 'Jihadi John'-style knife.

He used his agency job with a pharmaceutical firm as cover to scout United States Air Force (Usaf) bases in East Anglia for potential victims.

Detectives discovered he had been exchanging chilling online messages with an Islamic State (IS) fighter in Syria calling himself Abu Hussain.

Prosecutors claimed Hussain was British-born fanatic Junaid Hussain, who was killed in a US drone strike in the IS stronghold of Raqqa just weeks after his link with the planned UK attack was discovered.

One message described an attack on military personnel which they compared with the brutal murder of Fusilier Lee Rigby in Woolwich in 2013.

Sentencing him today at London's Kingston Crown Court, Mr Justice Edis said: 'Junead Khan was not far from the commission of the murder to be committed by horrifying method in the street in order to create terror and terrorist propaganda in this country.

'His offence was so serious that a life sentence must be imposed.'

Khan, from Luton, stared straight ahead as he was handed the sentence after being found guilty of preparing terrorist acts between May and July last year.

He will have to serve a minimum of 12 years.

He had also been found guilty of, jointly with his uncle, Shazib Khan, 23, preparing to go to Syria to join IS.

Shazib Khan was given an extended sentence of 13 years in prison. He will have to serve eight years in custody.

Police arrested Khan last July and discovered pictures on his phone of him posing in his bedroom with an IS-style black flag later found in the attic.

His computer was found to contain an al Qaida bomb manual and Amazon searches for a large combat knife.

Police officers had visited Khan as part of the national anti-extremism programme Prevent.

But the terror plotter had poured scorn on their attempts to speak to him and mocked the programme in a series of scathing WhatsApp messages.

Mr Justice Edis said the two men, who are of Bangladeshi backgrounds, have rejected the values and opportunities Britain gave them.

He said: 'They have both received education in this country at the public expense. They have lived as citizens of a free country which is committed to equality under the law.

'They both believe that Sharia law is the only legitimate law and both reject democracy because it involves law being made by people and not by God.

'They have rejected the protection of the law of this country and education they have received by becoming committed supporters of Isis (IS) - an organisation which wishes to control the world and which will stop short of no barbarity in order to do so.'