Treaties are agreements the UK has signed with other states and is therefore bound by.
As they are written down and the UK is unlikely to renege on its international obligations, they make the UK constitution partly codified and more entrenched.
This was especially the case when the UK was a member of the EU, as the EU treaties took precedence over UK statue laws passed by parliament.
Examples of treaties
The Uk signed the ECHR in 1951
It means the individual and bodies in the UK are bound to follow the convention and can be held to account by european court of human rights, which isnt part of the EU
2020 UK - EU withdrawal agreement established UK's exit from the EU
Statue law
Is the body of law passed by parliament. Most laws arent constitutional, only those that effect the political system and citizens rights are.
Only requires a simple majority to be introduced/changed/removed - they make the constitution flexible and unentrenched
examples of statue law
1969 representation of the peoples act lowered the voting age to 18
The parliament acts of 1911 and 1949 limited the power of the House of Lords
Human rights act1998 incorporated in the ECHR into the UK law
Scotland act and government of wales act
Authoritative texts
books that explain the workings of the british political system
they are sued as guide and do help to shape political landscape
but not binding and cant be the enforced by law though.
Examples of authoritative tects
AV dicey's study setting out parliamentary sovereignty and rule of law.
Common law
Common law is legal principles laid down by judges in their rulings on court cases which provide precedents for later judgements.
These are often clairifications on the exact implementation of statue laws passed by parliament.
It is important in cases where it isnt clear how statue law should be applied.
Example of common law
assumption that a person that is accused of a crime is innocent until proven guilty.