BRAMPTON, Ont. - The mastermind behind a "spine-chilling" terrorist plot that would have caused untold deaths and destruction was handed a life sentence Monday -- the maximum sentence under Canada's anti-terrorism laws -- though he's able to apply for parole in 2016.

Zakaria Amara, 24, whose religious ideology fuelled plans to set off massive truck bombs outside the CSIS and Toronto Stock Exchange buildings in downtown Toronto and at a military base in Ontario, is the first person to be given the maximum penalty for terrorist offences.

Ontario Superior Court Justice Bruce Durno said Amara's "spine-chilling" plot would have been "the most horrific crime Canada has ever seen."

"There is no dispute that what would have occurred was multiple deaths and injuries," he said.

As the three one-tonne ammonium nitrate bombs were supposed to explode at the end of the morning rush hour, "the impact would have been magnified as workers arrived for work. With one-tonne bombs at each location, the result would have been catastrophic," Durno said.

"This is one of those rarest of cases where the maximum sentence of life imprisonment is appropriate."

The Oklahoma City bombing in 1995 that killed 168 people used one tonne of ammonium nitrate.

The life sentence does not mean he will necessarily be jailed for life, but that if he receives parole he will be under supervision for the rest of his life. He is eligible to apply for parole 10 years after his arrest, which would be in just over another six years.

While others have pleaded guilty and have been sentenced in the plot, only Amara knew all the details and was the guiding force, Durno said.

"He committed a terrorist offence that would have had catastrophic and fatal consequences. He did not do so as a foot soldier. He did so as a leader," he said.

"In addition to the leadership role, Zakaria Amara was an active recruiter who influenced young men to become involved in a deadly plot. He led some to jail terms."

One of those young men was also sentenced Monday. Though Saad Gaya, 22, may have been a mere "helper" in the scheme, he should have foreseen its potentially horrific outcome, Durno said in sentencing Gaya to 12 years in prison.

Gaya, who also pleaded guilty to his role, and Amara were among 18 men and youths rounded up in 2006 and charged in what's known as the Toronto 18 terror plot.

Gaya has been in custody since his arrest. With 7 1/2 years credit for the time he has already served, Gaya was sentenced to serve another 4 1/2 years, but could be eligible for parole in 1 1/2 years.

Gaya was described in a psychiatrist's report as a sheltered young man -- he was 18 when he was arrested -- who was naive, immature and lacking in "street smarts." Still, he is an intelligent young man who could have put two and two together, the judge said.

"While the offender did not know how big the bombs were going to be ... he was wilfully blind as to the likelihood that there would be death or serious bodily harm," said Durno.

Terrorism offences "attack the very fabric of Canada's democratic ideals," he said.

Gaya's lawyer Paul Slansky said he disagreed with the judge's characterization of Gaya as "wilfully blind," and had been hoping for greater credit for Gaya's pre-trial custody, given that about one year of it was served in segregation.

At Amara's sentencing hearing on Thursday, the plotter read a letter to the judge and an open letter to Canadians, distancing himself from the extremist ideology that once consumed him.

"I have spent my entire life struggling to discover the truth and the reality of life," Amara told the court.

"But looking back retrospectively, I can also say that it is the same righteous struggled that led me down the road of extremism."

After he was sentenced today, Amara stood in court as family and friends wept and told Durno: "I just want to reassure you that whatever promises I made...I will still try my best."

As he was being led out of court he turned to his family, gave a weak smile and put his hand over his heart.

At his sentencing hearing Amara said he continued to hold his extremist views while in segregation for three years, but after his release into the general prison population several months ago he met many people who caused him to doubt his views and eventually renounce extremism.

Durno questioned the permanency of Amara's transformation.

"The depth and duration of his commitment will best be known in the future," he said.

Amara's lawyer, Michael Lacy, said Amara's remorse is genuine, and it took years for his views to become firmly entrenched, so they will not go away overnight, either.

"We're disappointed that at the end of the day he found that the only sentence that was appropriate in the circumstances is one that would see Mr. Amara sentenced for life," Lacy said outside court.

"He may be eligible for parole in 6 1/2 years. That doesn't mean that he will be parolled in 6 1/2 years."

The Royal Canadian Mounted Police released a statement Monday saying the Toronto 18 case "underscores the reality that Canada is not immune to the threat of terrorism."

"The extent of the preparations and the enormity of the attacks being planned in this case are quite chilling," the statement said.

Gaya was arrested along with Saad Khalid -- who was sentenced to 14 years but given seven years credit for pre-trial custody -- while they were unloading a delivery truck filled with what they thought was three tonnes of ammonium nitrate.

Of the 18 people arrested in 2006 seven have had their charges dropped or stayed, four people pleaded guilty, a youth was found guilty, one man's trial began last week and five others face a trial in March.