Section 20 of the Children Act 2004 (“the Act”) provides for the review of children’s services in the area of a children’s services authority in England (joint area reviews). “Children’s services” are defined by section 23(3) of that Act and regulations under that provision; “children’s services authority” is defined in section 63(1) of the Act. A review involves two or more of the persons and bodies listed at section 20(4); they may be requested to conduct a review by the Secretary of State, or may themselves decide to conduct a review. The purpose of a review is set out in section 20(3).