An al-Qaeda plotter who planned to kill thousands of people in the UK and US has been sentenced to life and told he must serve at least 40 years in jail.
Dhiren Barot, 34 and from London, had admitted conspiracy to murder.
The prosecution told Woolwich Crown Court Barot intended a "memorable black day" of terror and considered using a radioactive "dirty bomb".
Mr Justice Butterfield said the plot could have seen carnage on a "colossal and unprecedented scale" if successful.
'No noble cause'
Barot, a former Hindu who converted to Islam, is also wanted by US authorities over charges of conspiracy to use weapons of mass destruction in the US and in Yemen.
The judge told him: "This was no noble cause. Your plans were to bring indiscriminate carnage, bloodshed and butchery first in Washington, New York and Newark, and thereafter the UK on a colossal and unprecedented scale."
Home Secretary John Reid said the case showed "the terrorist threat remains very real and serious".
The prosecution conceded the police had not found any evidence that materials had been acquired to carry out the plans, but said officers had also failed to find weapons to which Barot had access.
Defence lawyer Ian Macdonald QC referred to the main part of the conspiracy as, in Barot's words, a "rough presentation".
Mr Justice Butterfield said Barot had not achieved any of his terror goals and that, on the evidence, he had not "moved to the final stages of achieving them". But he added that this was no thanks to him.
The court heard Barot prepared meticulous plans for al-Qaeda figures on a series of synchronised attacks in the UK.
"The central plan was for the construction and deployment in a basement car park underneath a building of an improvised explosive device using gas cylinders hidden in limousines," said Edmund Lawson QC, prosecuting.
Mr Lawson added it was to be launched simultaneously with other attacks including a dirty bomb, an attack on trains, and the hijacking of petrol tankers to be rammed into a target.
In the document, Barot had written his primary objective of the project was to "inflict mass damage and chaos".
The court heard Barot's plot also included plans to detonate a bomb under the River Thames to flood the Tube network and potentially drown hundreds of commuters.
Barot also planned to strike a number of US financial institutions. His plans for bombings in the US were initiated before the 11 September attacks, and Barot is not thought to have had any advance knowledge of them.
Barot's plans were found on a laptop computer seized during a raid on a house in Gujrat, Pakistan, in July 2004. The Muslim convert, from Kingsbury, north-west London, was arrested by armed police the next month.
Scotland Yard's anti-terrorist branch head, Deputy Assistant Commissioner Peter Clarke, called Barot a "determined and experienced terrorist" who attended training camps in 1995.
"For well over two years we have been unable to show the British public the reality of the threat they faced from this man. Now they can see for themselves the full horror of his plan."