The three accused in the Toronto 18 trial are, left to right, Steven Chand, Asad Ansari and Fahim Ahmad. (Alex Tavshunsky/CBC)

One of the ringleaders of the so-called Toronto 18 has pleaded guilty in mid-trial after a jury heard weeks of evidence that Fahim Ahmad led a terror cell plotting to attack Parliament and nuclear-power targets.

Ahmad, 25, was being tried along with Steven Chand and Asad Ansari on terrorism charges. It is the last of the trials associated with a group of 18 men and youth arrested in the summer of 2006.

"You look out here this morning, members of the jury, you'll see Mr. Ahmad is no longer with us," Justice Fletcher Dawson said Monday.

"Mr. Ahmad last week decided to change his plea to guilty."

Ahmad's plea has "no impact on the guilt or innocence of the two men who remain on trial," Dawson instructed the jury. The process that takes place when someone pleads guilty is not yet complete, but the trial must go ahead, Dawson added.

The jury heard earlier in the trial that Ahmad was the leader of a terror cell and held two training camps to assess his recruits' suitability to help him attack Parliament, electrical grids and nuclear stations.

They have already heard evidence that Ansari and Chand attended a training camp Ahmad held north of Toronto in December 2005.

Dawson told the jury that for them to find Chand or Ansari guilty at the end of the trial the Crown must have proven beyond a reasonable doubt that a terrorist group consisting of Ahmad and others existed. However, the Crown doesn't have to prove that Chand or Ansari were members of the group, just that they knowingly contributed to — whether directly or indirectly — the group's activities in furthering a terrorist plot.

All three men were charged with participating in a terrorist group, and Ahmad was charged with instructing people to carry out activities for a terrorist group and a weapons offence. The judge did not say if Ahmad pleaded guilty to all of the charges.

Chand also faces a charge of counselling to commit fraud over $5,000 for the benefit of a terrorist group.

Dozens of intercepts have been played for the jury, and in one Ahmad can be heard suggesting going to Parliament to "cut off some heads" and "kill everybody."

The jury was also shown a video of a fiery speech Ahmad gave at a terrorist training camp north of Toronto urging attendees to band together and sacrifice whatever was needed to defeat the empire of Rome, meaning Western civilization.

The video is dark except for Ahmad's face, which appears to be illuminated by a flashlight. The purported terrorist group leader is crouching under a white tarp in the snow, while a steady rainfall can be heard.

"[It ]doesn't matter what trials you face, it doesn't matter what comes your way," Ahmad says.

"Our mission's greater. Whether we get arrested, whether we [get] killed, we get tortured, our mission's greater than just individuals."

Police informant Mubin Shaikh, who attended the camp and even gave firearms training to the recruits, said all training camp participants were present to hear Ahmad's rousing speech. Many of the participants were quite young — one as young as 14, Shaikh has testified.

Ahmad also told camp participants later that they share the beliefs of al-Qaeda, Shaikh said. Though their group was not officially connected to al-Qaeda, "we're down with them," Shaikh quoted Ahmad as saying.

The video of Ahmad's speech was followed by video of Shaikh showing the other attendees how to use a 9-mm handgun. Several people in camouflage and masks can be seen standing around during Shaikh's handgun lecture and the whole scene is set to music, which Shaikh identified as jihad-themed music that says "kill the infidel."

Shaikh has identified Chand as a secondary leader of the Washago training camp.

Though many attendees did not know the true purpose of the camp when they arrived, everyone was well aware by the end, the Crown alleges.

Following Ahmad's speech, Shaikh was tasked with asking all the participants what they would do to further the cause when they got home, he testified. One man said he would help recruit people, Ansari said he would offer his computer expertise and the 14-year-old participant said he would give his allowance money to the cause, Shaikh said.