"Rule 1.7 Conflict of Interest: Current Clients
(a) Except as provided in paragraph (b), a lawyer shall not represent a client if the representation involves a concurrent conflict of interest. A concurrent conflict of interest exists if:
(1) the representation of one client will be directly adverse to another client; or
(2) the representation of one or more clients may be materially limited by the lawyer's responsibilities to another client, a former client, or a third person, or by a personal interest of the lawyer.
(b) Notwithstanding the existence of a concurrent conflict of interest under paragraph (a), a lawyer may represent a client if:
(1) the lawyer reasonably believes that the lawyer will be able to provide competent and diligent representation to each affected client;
(2) the representation is not prohibited by law;
(3) the representation does not involve the assertion of a claim by one client against another client represented by the lawyer in the same litigation or other proceeding before a tribunal; and
(4) each affected client gives informed consent, confirmed in writing."
https://www.ncbar.com/rules/printrule.asp?id=76
.
.
"Resolution of a conflict of interest problem under this Rule requires the lawyer to: 1) clearly identify the client or clients; 2) determine whether a conflict of interest exists; 3) decide whether the representation may be undertaken despite the existence of a conflict, i.e., whether the conflict is consentable; and 4) if so, consult with the clients affected under paragraph (a) and obtain their informed consent, confirmed in writing. The clients affected under paragraph (a) include both of the clients referred to in paragraph (a)(1) and the one or more clients whose representation might be materially limited under paragraph (a)(2).
[3] A conflict of interest may exist before representation is undertaken, in which event the representation must be declined, unless the lawyer obtains the informed consent of each client under the conditions of paragraph (b). To determine whether a conflict of interest exists, a lawyer should adopt reasonable procedures, appropriate for the size and type of firm and practice, to determine in both litigation and non-litigation matters the persons and issues involved. See also Comment to Rule 5.1. Ignorance caused by a failure to institute such procedures will not excuse a lawyer's violation of this Rule. As to whether a client-lawyer relationship exists or, having once been established, is continuing, see Comment to Rule 1.3 and Scope.
[4] If a conflict arises after representation has been undertaken, the lawyer ordinarily must withdraw from the representation, unless the lawyer has obtained the informed consent of the client under the conditions of paragraph (b). See Rule 1.16. Where more than one client is involved, whether the lawyer may continue to represent any of the clients is determined both by the lawyer's ability to comply with duties owed to the former client and by the lawyer's ability to represent adequately the remaining client or clients, given the lawyer's duties to the former client. See Rule 1.9. See also Comments [5] and [29] to this Rule.
[8] Even where there is no direct adverseness, a conflict of interest exists if a lawyer's ability to consider, recommend or carry out an appropriate course of action for the client may be materially limited as a result of the lawyer's other responsibilities or interests. For example, a lawyer asked to represent a seller of commercial real estate, a real estate developer and a commercial lender is likely to be materially limited in the lawyer's ability to recommend or advocate all possible positions that each might take because of the lawyer's duty of loyalty to the others. The conflict in effect forecloses alternatives that would otherwise be available to the client. The mere possibility of subsequent harm does not itself preclude the representation or require disclosure and consent. The critical questions are the likelihood that a difference in interests will eventuate and, if it does, whether it will materially interfere with the lawyer's independent professional judgment in considering alternatives or foreclose courses of action that reasonably should be pursued on behalf of the client.
