Convicted terrorist conspirator Zacarias Moussaoui made a startling admission Monday. Moussaoui told a federal court that he and convicted shoe bomber Richard Reid were supposed to hijack a fifth jetliner as part of the September 11, 2001, terrorist attacks and fly it into the White House.

Zacarias Moussaoui (2nd from left) being questioned by defense attorney Gerald Zerken (r)

Moussaoui took to the witness stand over the objections of his own defense lawyers.

He told the court that he knew the World Trade Center in New York was one of the 9/11 targets and that he lied about his knowledge of the plot after his arrest in August of 2001, some three weeks before the attacks, so that the plan would go ahead.

Last year, Moussaoui pleaded guilty to terror and conspiracy charges but said at the time that he did not know about the September 11 plot. He said then that he was supposed to be part of a second wave of al-Qaida attacks that targeted, among other things, the White House.

Moussaoui now says he and convicted shoe bomber Richard Reid were supposed to hijack a fifth airliner on September 11 and fly it into the White House.

Reid was subdued by passengers and crew in December of 2002 aboard an American Airlines flight from Paris to Miami. Reid was stopped as he tried to ignite explosives in his shoe. He was convicted of trying to blow up the airplane and sentenced to life in prison.

Moussaoui's surprising testimony came as part of the case being put on by his defense team.

Jurors in the case must decide whether to agree to the government's demand that Moussaoui be put to death for not revealing what he knew about the 9/11 plot when he was arrested three weeks before the attacks.

The only other option for the jury is to sentence Moussaoui to life in prison without the chance of parole.

In his testimony Monday, Moussaoui told the court that he knew the September 11 attacks were coming and that he bought a radio so he could listen to news coverage of the event.

Moussaoui said he knew little about the 9/11 plot from the beginning and only learned details of the operation gradually. But he says he did know most of the 19 hijackers who crashed the four planes on September 11, two into the World Trade Center in New York, one into the Pentagon and one into a field in Pennsylvania.

Prosecutors have previously presented evidence from FBI officials who said that had Moussaoui confessed his involvement when he was arrested, they might have been able to trace his involvement in the plot to some of the hijackers and perhaps unravel the plot.