The main sources of the U.K. constitution include statutes, common laws, conventions, international law and the European Union's legislation. The U.K. constitution is considered to be uncodified (an unwritten constitution).
Unlike many other world countries, there is no single document in Britain that outlines the specific laws of how the state works. Instead, the U.K. has several sources that are accumulated together to make a constitution. Statutes are the laws enacted by the parliament, and they are the highest on the land. Conventions are unwritten sources that are generated over time to regulate governing. Being a member of the European Union means that European law impacts the U.K. constitution. Also, lawyers and politicians depend on constitutional authorities for understanding the constitution.