Parliamentary or legislative supremacy is the concept that the governing parliament of a country or nation has supreme authority above all other departments or branches of government. It is often the governing principle in nations that have a strong or diverse parliament with clear constitutional authority. In nations that have had problems with totalitarian or autocratic monarchs or dictators, parliamentary supremacy may be asserted when the chance to restructure the government arises.
Many modern governments throughout the world have adopted systems of government that feature parliamentary supremacy. Many constitutional scholars assert that a nation with legislative supremacy has the purest form of democracy. Others argue that such a dispersion of authority can create excessive or unnecessary gridlock in government process.
The concept itself dates back to the establishment of the constitutional monarchy in 17th-century Great Britain when absolute monarchy was decisively rejected in favor of a government more directly influenced by the will of the people. Though the British Crown retained considerable authority, it lost many of the powers it had previously held to the British House of Lords and House of Commons. Historians regard this as the first step toward the establishment of parliamentary supremacy that would sweep Europe during the 18th and 19th centuries.
Throughout the 20th century, many small countries around the world established systems in which parliament is the supreme governing authority that supersedes all others. The United States is one of the few nations that spring from the English tradition that does not have a system of government based on parliamentary supremacy. Many European nations, including many of the former Eastern Bloc countries, have adopted parliamentary supremacy both as a way to dilute the power of a strong executive and to more easily mesh with the European Union (EU) in an effort to gain admittance.
Under governments where the parliament is considered supreme, there is no mechanism for judicial review, nor are there any checks and balances on parliament's authority or power. This issue was at the heart of the 1991 Factortame litigation, involving the EUs authority over member nations. The Factortame case found that the European Parliament had supremacy over the national governments of EU member states no matter what conflicts arose between national law and EU law. Also, the Factortame case established that the acts of the European Union's parliament were immune from judicial review or executive alteration.