What is the test for having sole custody of children?

Perhaps most controversially, the defendant seeks an order that he have sole custody of the children but that they primarily reside with the plaintiff. The defendant relies on the case of Metzner v. Metzner, [1993] B.C.J. No. 1839 (S.C.) as authority for that unusual order. The defendant maintains that the plaintiff’s decisions regarding the children’s relationship with him are such that the court must conclude that the plaintiff is either unable or unwilling to work in the children’s best interests as those interests relate to the children and their father. He maintains that he is capable of fostering a positive relationship between the children and both of their parents, and that the court should put the children in his custody so that that purpose may be achieved.