What Is Parliamentary Supremacy and What Limits It?

Parliamentary supremacy means that the UK Parliament can make or repeal any law. Courts must apply a valid Act of Parliament, even if they disagree with it, and one Parliament cannot prevent a future Parliament from changing the law. The key distinction is between legal limits, which would restrict Parliament’s power to legislate, and practical limits, which affect what it is likely to do.

Does Parliament face legal limits?

Under the traditional view of parliamentary supremacy, there is no general legal limit on what Parliament can legislate about. Courts can interpret Acts and review whether ministers have acted lawfully, but they cannot strike down an Act simply because it conflicts with a fundamental right.

The Human Rights Act gives courts a way to identify a conflict between an Act and protected rights. A court may issue a declaration of incompatibility, but the Act remains valid unless Parliament changes it. This is different from a court cancelling the law.

What limits it in practice?

Parliament must consider political pressures, public opinion and the consequences of its laws. Devolution gives institutions in Scotland, Wales and Northern Ireland powers to make laws in certain areas. By convention, the UK Parliament does not normally legislate on devolved matters without consent, but that convention does not remove its legal authority to do so.

International agreements can also create pressure to comply with commitments. They do not, by themselves, stop Parliament passing a conflicting Act. Similarly, a future Parliament can change or repeal legislation passed by an earlier one.

Exam mistake to avoid: do not say that human rights law or devolution means Parliament has lost its legal supremacy. Explain precisely whether you mean a legal restriction or a political and practical constraint.