In a case that altered airport security worldwide, three British Muslims were imprisoned Monday for at least 30 years each for a plot to kill thousands by blowing up trans-Atlantic airliners with liquid explosives hidden in soda bottles. The judge described the foiled suicide bombings - meant to rival the Sept. 11 attacks - as "a grave and wicked" conspiracy, likely the most serious terrorist case ever dealt with by a British court. The plot's disclosure prompted an immediate ban on taking some liquids onboard passenger jets, a measure that remains in place, inconveniencing passengers throughout the world. Abdulla Ahmed Ali - the plot's ringleader - was given a minimum of 40 years in prison, one of the longest sentences ever handed out by a British court. Assad Sarwar, 29, and Tanvir Hussain, 28, were imprisoned for a minimum of 36 years and 32 years respectively at London's high security Woolwich Crown Court. "The intention was to perpetrate a terrorist outrage that would stand alongside the events of Sept. 11, 2001," Judge Richard Henriques said, referring to attacks that killed nearly 3,000 people in New York, Washington and Pennsylvania. Henriques said the three men were the key figures in a plan to assemble and detonate liquid explosive bombs on aircraft bound for the United States and Canada in 2006. The explosives were to be stored in bottles that once carried Lucozade or Oasis sodas, with food dye added to make the mixtures resemble the original drinks. Authorities estimate that, if successful, about 2,000 passengers would have died - and if the bombs had been detonated over US and Canadian cities, hundreds more would have been killed on the ground. Prosecutors said the suspects had targeted seven flights from London's Heathrow airport to New York, Washington, San Francisco, Toronto, Montreal and two to Chicago. British and US security officials said the plan was directly linked to al-Qaida and guided by Islamic militants in Pakistan, who sent instructions to the group via coded e-mail messages. "The ultimate control of this conspiracy lay in Pakistan," Henriques said. A fourth man, Umar Islam, 31, who was found guilty of conspiracy to murder in the plot, was jailed Monday for a minimum of 22 years. Jurors were unable to decide in his case whether he knew that the eventual plot would target aircraft. Henriques told all four men they could spend their entire lives in prison if they are judged to continue to pose a threat to the public once they have completed the minimum requirements of their sentences. He said Ali, who read a small book and appeared distracted as his sentence was passed, had "an ambition to lead a terrorist outrage of boundless proportion." Ali's 40-year minimum sentence is among the highest jail terms ever meted out in Britain. Although judges can sentence convicted murderers to life without the possibility of parole, it is rare for convicts to spend their whole lives in prison. Only about 25 people have ever received sentences in Britain that condemn them to die behind bars. Police officials said they believe the plotters were just days away from mounting their attacks when officers rounded up dozens of suspects in August 2006. The arrests led to travel chaos as hundreds of jetliners were grounded across Europe. Investigators concede the group hadn't managed to produce a viable bomb at the time of their arrests or purchased airline tickets, but insist the plot was serious. "This was a viable and meticulously planned conspiracy and I conclude it was imminent," Henriques said. Sarwar's lawyer, Malcolm Bishop, told the court it was virtually impossible that the men could have constructed the bombs and carried them onboard undetected. It took government scientists 58 attempts over six months, and at a cost of 650,000 pounds ($1,078,000) to create a viable bomb using the plotters' design, Bishop said. Henriques dismissed his argument. Britain's chief prosecutor has said he will seek a retrial for three other men over their alleged involvement in the plot. A jury could not decide whether Ibrahim Savant, 28, Arafat Waheed Khan, 28, and Waheed Zaman, 25, were guilty of conspiracy to murder at a trial concluded last week. An earlier jury also was unable to agree on a verdict.