Why can courts in the United Kingdom interpret statutes but not invalidate acts of Parliament?

In the United Kingdom, courts cannot invalidate acts of Parliament because the country operates under the principle of parliamentary supremacy. Unlike nations with rigid, written constitutions that empower a judiciary to strike down legislation, the U.K. constitution is flexible and unwritten. Consequently, all statutes passed by Parliament are formally binding and can only be set aside or altered by subsequent acts of Parliament.12

While U.K. courts lack the power to invalidate primary legislation, they perform the essential judicial function of statutory interpretation. Courts are tasked with giving meaning and effect to the law, which involves using various legal tools and canons of construction to determine the legislature's intent. Furthermore, under the Human Rights Act 1998, courts are specifically obligated to read and give effect to legislation in a way that is compatible with convention rights.134

It is important to note that while parliamentary supremacy remains a foundational doctrine, it has been influenced by international obligations, such as those established by the European Union.15