What is the scope of confidentiality privilege in professional legal advice?

In Descoteaux v. Mierzwinski, 1982 CanLII 22 (SCC), [1982] 1 S.C.R. 860, 141 D.L.R. (3d) 590, Lamer J. (as he then was) described the scope of the privilege at pp. 872-873: Where legal advice of any kind is sought from a professional legal adviser in his capacity as such, the communications relating to that purpose, made in confidence by the client, are at his instance permanently protected from disclosure by himself or by the legal adviser, except the protection be waived. Further, in his conclusion at pp. 892-893: In summery, a lawyer’s client is entitled to have all communications made with a view to obtaining legal advice kept confidential. Whether communications are made to the lawyer himself or to employees, and whether they deal with matters of an administrative nature such as financial means or with the actual nature of the legal problem, all information which a person must provide in order to obtain legal advice and which is given in confidence for that purpose enjoys the privileges attached to confidentiality. This confidentiality attaches to all communications made within the framework of the solicitor-client relationship, which arises as soon as the potential client takes the first steps, and consequently even before the formal retainer is established.