The privilege is asserted in the face of a legal demand for the communications, such as a discovery request or a demand that the lawyer testify under oath.
This privilege exists when there is an attorney-client relationship.
Under the Model Rules of Professional Conduct, the attorney-client privilege exists for a potential client. Under Togstad v. Vesely, 291 N.W.2d 686 (1980), a non-client can claim to be a prospective client if: 1) the non-client seeks legal advice, 2) then the non-client reasonably relies on that advice as legal advice, and 3) the attorney does not attempt to dissuade the non-client from relying on the advice.
If the non-client is considered a prospective client under Togstad, then the attorney-client privilege will extend to that prospective client.