What is the test for setting aside solicitor/client privilege?

The central importance of the solicitor/client relationship to the proper functioning of the legal system is axiomatic. In Smith v. Jones, 1999 CanLII 674 (SCC), [1999] 1 S.C.R. 455 Cory J. stated as follows in this regard: 46. Clients seeking advice must be able to speak freely to their lawyers secure in the knowledge that what they say will not be divulged without their consent. It cannot be forgotten that the privilege is that of the client, not the lawyer. The privilege is essential if sound legal advice is to be given in every field. It has a deep significance in almost every situation where legal advice is sought whether it be with regard to corporate and commercial transactions, to family relationships, to civil litigation or to criminal charges. Family secrets, company secrets, personal foibles and indiscretions all must on occasion be revealed to the lawyer by the client. Without this privilege clients could never be candid and furnish all the relevant information that must be provided to lawyers if they are to properly advise their clients. It is an element that is both integral and extremely important to the functioning of the legal system. It is because of the fundamental importance of the privilege that the onus properly rests upon those seeking to set aside the privilege to justify taking such a significant step. Conflicts of Interest Based on Prior Representation