Law Practice Essentials

Former client conflicts are addressed in The Code of Conduct, Rule 3.4-6:

Unless the former client consents, a lawyer must not act against a former client:

• in the same matter;
• in any related matter; or,
• except as provided by Rule 3.4-7, in any other matter if the lawyer has relevant confidential information arising from the representation of the former client that may prejudice that client.

Remember that “consent” in the context of these Rules means that it is fully informed and voluntary consent, after disclosure.  See commentary to Rule 3.4-1.

You are not permitted to act against former clients on a related matter, as this would undermine the work previously done for your former client.

This Rule is meant to protect confidential information obtained from clients.  You may not act against a former client where confidential information obtained during the retainer may be used to that client’s disadvantage. Conversely, if you have confidential information about a former client and do not use it to assist a new client, you will fail to fulfil your duty to provide full representation to the new client.  Without consent, you are prohibited from acting against a former client if you have prejudicial confidential information about the client, even if the matters are unrelated.

In MacDonald Estate v Martin, 1990 CanLII 32 (SCC), [1990] 3 SCR 1235, the SCC identified two questions that must be addressed when considering a “former client” conflict:

1. Did the lawyer receive confidential information attributable to a solicitor and client relationship relevant to the matter at hand? To meet this requirement you must, without revealing specifics of the privileged communication, satisfy the court that a reasonable member of the public would accept that no confidential information relevant to the new matter passed you and your client during the conduct of the previous matter. If it is shown that a previous relationship (sufficiently related to the retainer) existed, the court will likely infer that confidential information was imparted unless you can discharge the burden of showing that no relevant information could be imparted.
2. Is there a risk the confidential information will be used to the prejudice of the client? If you have relevant information, you are automatically disqualified from acting against a client or former client. Further, there exists a strong inference that lawyers who work together share confidences, and clear and convincing evidence is required to show that all reasonable measures have occurred to ensure no disclosure will take place between the lawyer who possesses confidential information about the client against whom another lawyer in the firm is acting.
   

Consider the following situations that would constitute a conflict:

• You have helped set up a large number of asset structures for Client A to minimize tax liabilities, and you have now been asked to represent A’s wife in their divorce proceedings.
• You defended B in a criminal case related to an assault of C, and now C wishes to retain you to bring a civil suit in relation to that same assault.

In both situations, you would have learned prejudicial confidential information while acting for the first client which will prevent you from representing the new client.