In all cases in which the paternity of the child has not been established to the satisfaction of the county department, the county department shall refer the applicant to local child support agency at the time the application is signed. Upon the advice of a county department that a child is being considered for adoption, and regardless of whether or not the whereabouts of the parent is known, the local child support agency shall delay the investigation and other action with respect to the case until advised that the adoption is no longer under consideration. The
local child support agency shall conduct such investigation as the agency considers necessary, and where he or she deems it appropriate, the agency may bring an action under Chapter 4 (commencing with Section 7630) of Part 3 of Division 12 of the Family Code. When the cause is at issue, it shall be set for trial at the earliest possible date and shall take precedence over all other cases except older matters of the same character and matters to which precedence may be given by law.