HALIFAX - A new court martial for a former soldier charged in the fatal shooting of a fellow reservist in Afghanistan began Tuesday before a military judge with the defence arguing a manslaughter charge against him should be dropped.

Matthew Wilcox of Glace Bay, N.S., was found guilty in July 2009 of criminal negligence and negligent performance of duty in the death of Cpl. Kevin Megeney of Stellarton, N.S.

However, the Court Martial Appeal Court of Canada set aside his guilty verdict last year after Wilcox's lawyers argued the makeup of a military jury was unfair.

Military prosecutors then requested a new trial in the death of Megeney, 25, who died after he was shot in his tent in Kandahar on March 6, 2007.

In the appeal, Wilcox's legal team argued the military panel hearing the case should have consisted of five members, instead of only four. One member on the panel was excused due to a conflict with a work commitment but he wasn't replaced with an alternate.

Wilcox's defence lawyer David Bright argued Tuesday that the original charge of manslaughter should be dropped in the new trial, which is being held in Halifax before a military judge, Lt.-Col. Louis-Vincent d'Auteuil.

The manslaughter charge was stayed in the original military trial in Sydney.

The judge reserved his decision on Bright's argument until Wednesday.

Wilcox was sentenced to four years in prison and kicked out of the military at his first court martial.

During that trial, the prosecution put forward the theory that Wilcox and Megeney were playing a game of "quick draw" in their tent at the Kandahar Airfield base when Wilcox's loaded pistol accidentally fired, hitting Megeney in the chest.

Wilcox said it was a case of self-defence, testifying that he shot "instinctively" against an unknown threat that was pointing a gun at his back inside the tent he shared with Megeney.