Parliamentary sovereignty means that parliament is superior to the executive and judicial branches of government, and can therefore enact or repeal any law it chooses. It is a cornerstone of the UK constitutional system and also applies in some parts of the Commonwealth such as Canada. The idea of parliamentary sovereignty is neatly summed up by 19th century constitutional theorist A V Dicey:
“Parliament…has, under the English constitution, the right to make or unmake any law whatsoever; and, further, …no person or body is recognised by the law of England as having the right to override or set aside the legislation of Parliament.”
In theory, the UK parliament could enact legislation which oppresses 95% of the population if it chose to do so, however the political consequences of such a measure mean that in practice this is very unlikely to happen.
The notion of parliamentary sovereignty was at the heart of the Brexit referendum in 2016. Those wishing to leave the European Union saw its institutions, such as the European Parliament, as directly challenging the sovereignty of the Westminster Parliament because European laws can be automatically binding and override local laws within the UK. On the other hand, it was the Westminster Parliament which accepted some limits on its own sovereignty when it decided to join the European Union (then known as the European Economic Community) in 1972 when it passed the European Communities Act.
Canadian parliamentary sovereignty
In Canada, the provinces have legislative sovereignty in some matters as well. In addition, federal parliament is sovereign in several areas but the majority of amendments to the Canadian Constitution can only be made with the consent of two-thirds of the provinces which represent 50% of the Canadian population.
See also: Bill of Rights
, Branches of Government