BRAMPTON, Ont - The first trial for one of the suspects charged in the alleged Toronto terror plot of 2006 formally began Tuesday with a partial publication ban and a preview of evidence that the Crown calls "shocking and sensational."

The accused, who was charged under the Youth Criminal Justice Act and cannot be named, was arraigned and pleaded not guilty. He is charged with participating in and contributing to the activity of a terrorist group.

The Crown will present evidence that proves the youth attended a training camp where he participated in military exercises and firearms training, said Crown attorney Marco Mendicino.

He asked for a partial publication ban to prevent the media from linking evidence at the trial to any of the other suspects by name, saying the evidence is "palpably prejudicial" and could destroy any chances of the other suspects getting a fair trial when their cases go to court.

Mendicino said evidence related to the alleged training camp is the "centrepiece of the case." He said the evidence would likely be "reprehensible" to the average Canadian, and the prejudicial effect would be long-lasting.

Mendicino said he was especially concerned about fairness for the suspects since media interest in the case has been unprecedented, with 4,710 news stories published in the first two weeks after the arrests in the summer of 2006.

The judge did not immediately rule on the application, but put in place an interim ban preventing names or other identifying information from being published regarding any accusations heard in court.

But the interim ban and the ban sought by the Crown do not block the media from reporting specific details of evidence presented during the trial.

Lawyer Paul Schabas, who represented several media outlets, said there should be no publication ban at all because the public has a right to know what's going on inside the courtroom, which ordinary citizens are free to enter.

"The public has a right to know about it as if it was sitting in this courtroom," he said.

"This court must do whatever it can ... to find a way to argue this as much as possible in public."

Schabas also argued the Crown cannot prove the evidence would definitely taint the opinions of future jurors.

"Saying that it's so doesn't make it so," he said, adding that "an accused isn't entitled to an ignorant jury," just an impartial one.

Although the trial officially began Tuesday, the first witnesses are not expected to be called until May 27. Before then, defence lawyers will launch two constitutional challenges regarding the charges that were originally laid and wire taps that were used to gather evidence.

One of the first witnesses is expected to be Mubin Shaikh, a former Canadian army cadet and Islamic law activist who went public with his story of how he infiltrated, trained and spied on the alleged cell members leading up to their arrests.