Barot was called a "determined terrorist" by Scotland Yard
Barot's surveillance
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.
For well over two years we have been unable to show the British public the reality of the threat they faced from this man
DAC Peter Clarke
Scotland Yard
Profile: Dhiren Barot Round-up of prosecution case
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.
Mass damage
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."
Today, in Woolwich Crown Court, Dhiren Barot was sentenced to life imprisonment having been found guilty of conspiracy to murder. 

Evidence was presented that Barot had planned, among other things, to bomb prominent buildings in Britain including the Savoy Hotel, to discharge  'dirty' bombs and to destroy a tube train under the Thames with the intention of flooding the underground system.

Barot was the author of a terrorist's handbook published in Birmingham in which he upheld the IRA as an example to be followed, although he thought that their methods were a bit out of date. 

Barot had planned to attack buildings in the United States before 9/11, but, it was thought, he had no prior knowledge of that attack.

In delivering the sentence, the judge, Mr Justice Butterfield, told Barot that he must serve at least 40 years before he would be considered for release.