Parliamentary sovereignty, also called parliamentary supremacy or legislative supremacy, is a concept in the constitutional law of some parliamentary democracies. It holds that the legislative body has absolute sovereignty and is supreme over all other government institutions, including executive or judicial bodies. It also holds that the legislative body may change or repeal any previous legislation and so it is not bound by written law (in some cases, not even a constitution) or by precedent.
In some countries, parliamentary sovereignty may be contrasted with separation of powers, which limits the legislature's scope often to general law-making and makes it subject to external judicial review, where laws passed by the legislature may be declared invalid in certain circumstances. However, in such countries the legislative body still retains the sovereignty by the possibility to alter the constitution, which usually requires greater majority, often 2/3 of votes instead of 1/2.
Many states have sovereign legislatures, including the United Kingdom, New Zealand, the Netherlands, Sweden, Norway, Denmark, Finland, and Jamaica.
Under the federal system, neither the states nor the federal parliament in Australia have true parliamentary sovereignty. The Commonwealth Parliament is created by the federal constitution, and only has enumerated powers. Each state's legislative power is inherent but restrained by the federal constitution, the relevant state constitution, and Commonwealth powers. Nevertheless, in the Australian context, 'parliamentary supremacy' is used contextually as a term and has two meanings: one is that parliament (the legislature) can make and unmake any law; another meaning is that as long as a parliament (legislature) has the power to make laws regarding a subject matter, the exercise of that power cannot be challenged or reviewed by the judiciary. The second meaning is more consistent with the federal system and the practice of judicial review, as the judiciary cannot review on the merits of the parliament (legislature)'s exercise of power.