Constitution of the United Kingdom
Using the word "unwritten" is a problem, because most British laws and rules are written as statutes, or court judgments, the law of equity and in various treaties. Most of these laws come from the Parliament of the United Kingdom. Because most of the constitution is written down in this way, it is not technically correct to call it "unwritten" or "de facto". However, these words are still used. The Constitution of the United Kingdom of Great Britain and Northern Ireland is even more different to most other constitutions in that it is just a normal set of laws, and not a "higher" law that the government cannot easily change. The constitution has no more authority than any other law in the UK, and the government can change it just by passing a new Act.