Sept. 14 (Bloomberg) -- Three U.K. men convicted of plotting to blow up trans-Atlantic passenger jets in mid- flight were each sentenced to more than 30 years in prison today.

Justice Richard Henriques in London issued the sentence, calling the plot “most grave and wicked conspiracy ever proven” in England. A jury convicted the men, -- Ahmed Ali, Assad Sarwar, Tanvir Hussain -- on Sept. 7. Ali was sentenced to a minimum of 40 years, Sarwar at least 36 years and Hussain at least 32 years.

They were found guilty of planning to blow up seven planes using liquid explosives carried in soft-drink cartons. The probe changed airport security policies, leading authorities to require passengers to put liquids, pastes and gels into clear plastic bags when passing through checkpoints and impose strict limits on the amounts of carry-on fluids.

“I am satisfied that there was every likelihood this plot would have succeeded but for the intervention of the police and the security services,” Henriques said today.

Henriques rejected arguments by the men’s lawyers today that the conspirators were months away from being able to carry out an attack, and would have probably failed if they did.

No ‘Serious Attempt’

“What we have here is a conspiracy and not a serious attempt,” Nadine Radford, Ali’s lawyer, told the judge. She said her client was “capable of change.”

The judge sentenced a fourth man, Umar Islam, to a minimum term of 22 years. The jury had convicted him of the lesser charge of conspiracy to murder. The judge said he was a “foot solider” who was kept unaware of the target of the plot.

They were part of a group of eight British Muslims put on trial. Prosecutors are seeking a retrial for Ibrahim Savant, Arafat Waheed Khan and Waheed Zaman on the charge of conspiracy to murder after the jury was unable to reach a verdict, a spokesman for the Crown Prosecution Service said. The men were cleared of a more serious charge.

Another man was found not guilty on the two main counts.

To contact the reporter on this story: James Lumley in London at jlumley1@bloomberg.net.

Last Updated: September 14, 2009 10:11 EDT