To what extent might the constitution of the United Kingdom be improved if provisions from the constitutions of other states were incorporated into it?

All modern states have a constitution, albeit each is very different. The main purpose of a constitution is to restrain government, in the sense of ensuring that governments are not arbitrary. Government must be carried out according to established rules. These rules are the constitution. The existence of a constitution also protects the individual, not just from the power of the government, but also from other powerful bodies and individuals. It is also the constitution, which grants a government the right to rule, thereby legitimizing authority. This essay is concerned with the incorporation of provisions from other states that might improve the present constitution of the UK. Accordingly, this essay deals with three substantive constitutional provisions, namely the entrenchment of a bill of rights, similar to that which exists in Canada, the correct application of the doctrine of separation of powers, as exists in America, and finally the establishment of a Constitutional Court, similar to that of Germany.

[...] Lord Steyn, the law lord, also supports the importance of “clear separation of powers”.[13] Indeed, provisions can be implemented whereby the executive is not fused with the legislature, for instance the Lord Chancellor’s Department, which in its current form has been held questionable by the European Court, should be abolished, and replaced by a Department of Law whereby the Secretary of the State would be an MP, without an overlap with the legislature and judiciary, as suggested by Brazier.[14] With regards to the judiciary, whilst it ‘correctly’ cannot control the legislature, the influence it has over the executive needs to be separated, and re-applied in the form of a Supreme Court, as proposed by Lord Steyn (discussed below), perhaps with the power of declaring statutes unconstitutional, although such situations would be less apparent in the UK due to the unwritten constitution. [...]

[...] Oliver, A Bill of Rights for the UK, in Government in the UK (Milton Keynes: Open University Press 1991). Dworkin, A Bill of Rights for Britain, (London: Chatto & Windus, 1990). S. E. Finer et al., Comparing Constitutions, (Oxford University Press, 1995), Chapter 4. Myers v. US 272 US 52 (1926). Marbury v. Madison 1 Cranch US) 137 (1803). Shaw v. DPP (1962) AC 222. H. Fenwick, Constitutional & Administrative Law, 3rd edn, (London: Cavendish Publishing, 1999), Chapter 9. R (1991) 2 All ER 634 S. [...]

[...] A clear illustration of the theory can be seen from the US Constitution.[6] Article 1 of the constitution (1787) states that the legislative power shall belong to Congress. Congress is elected separately from the President and may turn out not to be of the same political persuasion. Article 2 states that the executive power belongs to the President. The President and his Cabinet are not permitted to be members of the Congress. Lastly, Article 3 declares that the judicial power belongs to the Supreme Court and inferior courts as may be created. [...]