A British Islamic extremist has been jailed for life for planning a terror attack on American military personnel in the UK.

Junead Khan, 25, was a “committed supporter” of Islamic State and plotted to kill a soldier with a knife like the one used by Mohammed Emwazi, the notorious Isis extremist known as “Jihadi John”, whom he idolised.

Khan used his agency job as a delivery driver with a pharmaceutical firm as cover to scout US air force bases in East Anglia for potential victims.

Detectives discovered he had been exchanging chilling online messages with an Isis fighter in Syria calling himself Abu Hussain. Prosecutors said Hussain was the British-born fanatic Junaid Hussain, who was killed in a US drone strike in the Isis stronghold of Raqqa weeks after his link with the planned UK attack was discovered.