At a trial on several charges, the Crown had sought to call the common law spouse of the accused. The accused’s spouse was intended to be the Crown’s main witness. The spouse did not wish to testify. The trial judge ruled that the traditional common law rule that provided that married spouses were not compellable to testify against each other was discriminatory against those who lived in common law relationships comparable to that of married couples, and ought to be modified to provide protection to common law spouses as well. Given that the intended key witness could not be called, the Crown called no evidence and an acquittal was entered. The Crown appealed the acquittal, arguing that the trial judge’s ruling on the non-compellability of common law spouses was in error.
Madam Justice Paperny, writing for a unanimous panel of the Alberta Court of Appeal in a reserved judgment (2014 ABCA 213), concluded that the common law rule against compellability of spouses to testify against each other should be extended to common law spousal relationships, where such relationships have “a bond involving a level of commitment that corresponds to marriage” (at para. 41).
The Court described the extension of this rule as an incremental change to the common law, noting:
 … The privilege is that of the witness, not the accused. It must be asserted by the witness who will then bear the burden of establishing that the relationship is one with a substantive marital bond. Determining whether a marital bond exists between common-law spouses is no more difficult than determining if legally married spouses are irreconcilably separated. The inquiry will be simple if, for example, the common-law spouses in question had executed an adult interdependent partner agreement under the AIRA [Adult Interdependent Relationships Act]. This would be akin to an irreconcilably separated spouse producing a declaration of irreconcilability under s 83 of the Family Law Act.  Where there is no legal instrument that resolves the matter, the trial judge would have to hear evidence and inquire into the facts of the relationship. The guiding principles would be those set out by L’Heureux-Dubé J in Miron: a relationship analogous to marriage, with some degree of publicly acknowledged permanence and interdependence.
While the trial judge in Legge had also ruled that common law spouses were incompetent to testify against each other, the Court of Appeal refused to confirm this aspect of the trial judge’s ruling, noting that it was not necessary to decide that issue on the facts of the case.
The Court noted that following the argument of the appeal, but prior to the release of the decision, a bill had been introduced by the federal Parliament to completely repeal the common law rule that spouses are non-compellable and incompetent to testify against each other (replacing earlier provisions of the Canada Evidence Act which had modified the common law rules with respect to specific circumstances and offences, but not completely reversed it). The proposed statutory amendment can be found at s. 52 of Bill C-32, the Victims Bill of Rights Act. That bill received second reading and was referred to committee on June 20, 2014.