At a disposition hearing, a review hearing, or at any other hearing regarding a dependent child, the court must not set a hearing under section 366.26 to consider termination of the rights of only one parent unless that parent is the only surviving parent, or the rights of the other parent have been terminated by a California court of competent jurisdiction or by a court of competent jurisdiction of another state under the statutes of that state, or the other parent has relinquished custody of the child to the county welfare department.
Cal. R. Ct. 5.705