What must a lawyer obtain from a former client before representing another in a substantially related matter?

A lawyer must obtain informed, written consent from a former client before representing another party in a substantially related matter due to the potential for a conflict of interest. This requirement is grounded in the Model Rules of Professional Conduct, which aim to protect client confidentiality and maintain the integrity of the attorney-client relationship.

When a lawyer has previously represented a client, they have gained access to sensitive information that could be detrimental to the former client if used in a new case against them. By requiring informed, written consent, the rules ensure that the former client is fully aware of the implications of allowing the lawyer to take on the new representation and can weigh the consequences before agreeing.

Additionally, obtaining written consent provides clear documentation of the former client’s agreement, which can be essential in case any disputes arise regarding the representation. This procedure helps preserve the trust between clients and lawyers and maintains ethical boundaries in legal practice.