Judicial review refers to the power of the judiciary to review actions of the executive and legislature and invalidate laws or actions that are incompatible with higher authority such as a constitution. While India's constitution does not expressly provide for judicial review, it is considered an integral part of the system as it upholds the supremacy of law and allows courts to declare laws inconsistent with the constitution as void. In the UK, judicial review originally only applied to subordinate legislation but courts have increasingly reviewed primary legislation as well, strengthened by the 1998 Human Rights Act.