4. Conventions
e.g. regarding the royal prerogative, collective ministerial responsibility, or the Govt resigning if defeated on a vote of no confidence. They have no force in law but are adhered to and taken very seriously.
5. International treaties
e.g. when the UK signed the Treaty of Rome in 1972 to join the EC in 1973. Also membership of international bodies such as the UN or NATO affects British sovereignty.
6. Academic treatises
i.e. learned academic books on the constitution which are considered so authoritative that they are virtually part of the constitution e.g. Walter Bagehot, A.V. Dicey or Erskine May.
The UK constitution is flexible rather than rigid – meaning that no special procedures are required to alter it. In Britain any Act of Parliament, judicial decision, foreign treaty is deemed to be part of the constitution if it relates in any way to the constitution. For example, the Human Rights Act 1998 or the Maastricht Treaty 1991, because they both have constitutional implications are considered to be part of the constitution. The constitution is therefore constantly evolving.
The UK is a unitary state. This means power (sovereignty) rests in the centre. It may be devolved to the regions (e.g. the Scottish Parliament) but can be taken back at any time by Parliament.
The UK has a system of parliamentary government – the executive (PM Cabinet etc.) is DRAWN FROM and ACCOUNTABLE TO Parliament. This is very different from presidential systems such as in the US. Britain therefore has a parliamentary executive – the executive is not independently elected but is formed by the leader of the largest party in the Commons elected in the general election.
In Britain there is a fusion of powers rather than a separation of powers. Executive and legislature overlap because the Government sits in Parliament. The monarch is a member of Parliament (e.g. Royal Assent), it is Her Majesty's Government and they are HER courts (e.g. QCs). In particular, there is criticism of the Lord Chancellor's position as head of the judiciary, a Cabinet member and Speaker of the House of Lords.
A.V. Dicey identified what he called the 'twin pillars' of the UK constitution – these were parliamentary sovereignty and the rule of law. Parliament has the right to make or unmake any law. There is no form of higher law in Britain. All statutes are of equal force and no Parliament can bind its successors. Ultimate power therefore rests with Parliament. The rule of law ensures that all citizens will be treated equally before the law. No-one is above the law. People cannot be imprisoned without a fair trial and people's rights are not arbitrary but are the result of judicial decisions.
Britain has an independent judiciary. Judges are supposed to be impartial and have security of tenure – i.e. serve until they retire rather than being replaced by any incoming government.
