The UK has a real constitution. A central side of it is HRA 1998 which Tory/Reform want to do away with because it curtails power of government.

A real constitution is not a vague collection of traditions. Every other country understands "constitution" to mean a written document. A collection of traditions cannot meet the primary aim of a constitution, which is granting people clear and unambiguous rights.

Furthermore, a constitution is generally more difficult to change than a law. The Human Rights Act can be repealed by a simple majority of MPs voting to repeal it.