Does a lawyer owe confidentiality to a former client?

Second, a lawyer owes a duty of confidentiality to a former client in respect of confidential information received in the course of a solicitor-client relationship: see Macdonald Estate v. Martin, 1990 CanLII 32 (SCC), [1990] 3 S.C.R. 1235 at pages 1259-1261. In that decision, Sopinka J. articulated a rebuttable presumption: “once it is shown by [a former] client that there existed a previous relationship that was sufficiently related to the retainer from which it is sought to remove the solicitor, the court should infer that confidential information was imparted unless the solicitor satisfies the court that no information was imparted which could be relevant.” Sopinka J. also stated that application of the principle is predicated on a client actually objecting to the retainer that gives rise to the alleged conflict.