SKWEYIYA J continuing validity of the provisions, this Court’s judgment could be sent to magistrates and judges so as to emphasise the continuing effect of the statutory provisions. It seems to me that such an approach addresses concerns about uncertainty without compromising the crucial principles raised in this judgment. [219] In any event, Ngcobo J’s factors are not exhaustive of the relevant factors in the interests of justice enquiry where constitutional issues were improperly raised by the lower court. It is to these additional factors that I now turn. Constraints on judicial authority: the rule of law and the separation of powers [220] In my view, the first additional factor that should inform our interests of justice enquiry in this case concerns the rule of law and the separation of powers. Although courts are independent and subject only to the Constitution and the law,8 it is the judiciary’s continued respect for these two principles that preserves its integrity and independence. As Cameron notes: “The institutional and substantive independence of the judiciary is of great importance. But it is a value only in its interrelation with other values: judicial independence is guarded because it is meant to serve the public interest through the separation of powers and fidelity to the rule of law.” 9 (My emphasis.) [221] In the tripartite division of public power, courts are entrusted with a specific and limited function. The judiciary is the ultimate guardian of the Constitution, 8 Section 165(2) of the Constitution. 9 Cameron “Judicial Accountability in South Africa” (1990) 6 South African Journal on Human Rights 251 at 264. 111