The constitution
A set of rules determining where sovereignty lies in a political system, and establishing the relationship between the government and the governed.
Uncodified/codified
An uncodified constitution is not contained in a single written document, unlike a codified constitution which is written in a single authoritative document.
Unitary/federal
A unitary political system is one where all legal sovereignty is contained in a single place, unlike a federal system where legal sovereignty is shared between a national government and regional governments
Parliamentary sovereignty
The principle that Parliament can make, amend or unmake any law and cannot bind its successor nor be bound by its predecessors.
Conventions
Traditions not contained in law but influential in the operation of a political system.
Common law
Laws made by judges in cases where the law does not cover the issue or is unclear
Rule of law
The principle that all people and bodies, including government, must follow. The law and can be held to account if they do not.
Unentrenched/entrenched
An unentrenched constitution has no special procedure for amendment, unlike an entrenched one which requires separate rules and procedures for amendment.
Quasi-federalism
A system of devolution where it is so unlikely or difficult for power to be returned to central government that it is, to all intents and purposes, a federal system even though it is not in strict constitutional terms
Statute law
Law passed by Parliament.
Authoritative work
A work written by an expert describing how a political system is run. It is not legally binding but is taken as a significant guide.
Treaties
Formal agreements with other countries, usually ratified by Parliament.
Devolution
The dispersal of power but not sovereignty within a political system.
Hereditary peers
Members of the aristocracy who owe their title to brith, in other words they inherit their title usually from their father. Some titles go back deep into history. Ninety-two such peers have a right to sit in the House of Lords.
Independence of the judiciary
Under the separation of powers, the three branches of government- legislature, executive and judiciary - are independent. They have separate powers and can check each others power.
Asymmetric devolution
A type of devolution where the various regions have been granted unequal amounts of power .
The West Lothian question
An issue raised in 1997 by the Labour MP for West Lothian, Tam Dalyell, which concerned the problem of MPs sitting in the House Of Commons and representing devolved areas such as Scotland, Wales and Northern Ireland, being able to vote on matters that would only affect England, while English MPs could not vote on those issues that have been passed to devolved bodies such as education and healthcare.