What are the core primciples of the UK constitution?

The rules and regulations within which governments are allowed to operate are set out in constitutions. Most countries’ constitutions are ‘codified’, which means that they are largely made up of, or based around, a single written document incorporating key provisions. However, the UK does not have a codified constitution like this.
The UK does not have a single core constitutional document and is therefore sometimes referred to as not having a written constitution. However, the UK’s constitution is made up of some written documents, such as statute law, court judgments and European legislation, but has also developed from case law, common law, historical documents and custom. Therefore, it has more accurately been described as uncodified. Unwritten conventions deriving from understandings and customs are considered to be binding, despite not being  within statute or supported by law.
A historic feature of the UK constitution is the Royal Prerogative. These powers are formally exercised by the monarch acting alone, but in reality are exercised by government ministers. It gives the Crown many powers including the power to declare war, make treaties, deploy armed forces, appoint and dismiss ministers and dissolve parliament. In reality, the existence of the Royal Prerogative within the UK constitution means that the Government can exercise its powers without recourse to Parliament.
The most important principles of the UK constitution are those of parliamentary sovereignty and the rule of law. The former means that Parliament can make or unmake any law without being bound by, or binding, its predecessors or successors respectively.
Parliamentary sovereignty therefore means that Parliament is the supreme law-making body, although this is now challenged by the UK’s European Union membership, which gives European laws superiority over any conflicting domestic law. Also, over the years, the application of parliamentary sovereignty has been limited by the passing of certain laws by Parliament, such as the Human Rights Act 1998.
The rule of law incorporates fundamental principles to which the Government and the law have to conform. For example, this includes the principle that ‘no person is punishable in body or goods without a breach of the law’, meaning that individuals will not be punished unless they have committed a clear breach of the law.