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A British man who was supposed to take down an airplane with a shoe bomb in 2001 until he backed out of the conspiracy is set to resume testimony in the trial of Osama bin Laden's son-in-law with a description of what happened in the weeks after the terrorist attacks.

Prosecutors began questioning Saajid Badat on Monday to try to show that then-al-Qaida spokesman Sulaiman Abu Ghaith knew what he was talking about when he threatened Americans in the weeks after Sept. 11 with a second wave of airplane attacks.

Badat, a 34-year-old United Kingdom resident, is expected to testify all day Tuesday by video hookup from London. He refuses to testify in the United States because he faces terrorism charges in Boston that could send him to prison for life.

On Monday, Badat said he trained with failed shoe-bomber Richard Reid to carry out separate shoe-bomb attacks aimed at downing planes over America or Europe in the months after the Sept. 11 attacks were carried out with four hijacked airplanes.

He pleaded guilty in England in 2005 to conspiring to harm an aircraft and served six years in prison before his sentence was shortened through his cooperation. His plea came in connection with a 2001 plot to down an American Airlines flight from Paris to Miami with explosives hidden in his shoes.

Prosecutors are using Badat's testimony to show that Abu Ghaith was in the thick of a conspiracy to create a second wave of airborne terrorism attacks while the debris left by the toppled twin towers of the World Trade Center was still burning.

Abu Ghaith is charged with conspiring to kill Americans and providing material support to al-Qaida. If convicted, the 48-year-old onetime imam at a Kuwaiti mosque could face life in prison. He has pleaded not guilty.

Immediately before Badat's testimony, prosecutors showed jurors a 50-second clip of a 5-minute videotape of Abu Ghaith from Oct. 9, 2001, in which he threatens that "America must know that the storm of airplanes will not abate, with God's permission." Alluding to martyrdom, he said there were "youths who are yearning to death just as Americans yearn to live."

Then prosecutors showed nearly 2 minutes of an 8-minute videotape from Oct. 13, 2001, in which Abu Ghaith threatens America again, saying some in the U.S. had not understood the gravity of his earlier message.

"The storm of aircrafts will not stop," he said at one point, according to an English translation of Arabic statements that was introduced as a court exhibit. "We strongly advise Muslims in America and the Britain, the children and those who reject unjust American policies, not to board aircraft and we advise them not to live in high-rises and tall buildings."

Despite many months spent in al-Qaida training camps and locations in Afghanistan from 1999 through 2001, Badat testified that he did not recognize a photograph of Abu Ghaith and did not recall having ever seen or heard him.

Badat said he had seen bin Laden as many as 50 times during his time in camps and guest houses.

During testimony at a 2011 Brooklyn terrorism trial, Badat said bin Laden told him shortly after the Sept. 11 attacks that he believed a follow-up terrorism attack could doom the American economy.

He said he backed out of the shoe-bomb plot in December 2001 because of his reluctance, fear and the effect it would have on his family.

Abu Ghaith is the highest-ranking al-Qaida figure to face trial on U.S. soil since 9/11.