WRITTEN CONSTITUTION VERSUS PARLIAMENTARY CONVENTIONS
There's an active debate in political circles about the pros and cons of written constitutions, especially in the United Kingdom, whose political system has evolved from centuries of conventions, precedents, parliamentary procedures and generations of government legislation. The United States is quite rightly first on the list of successful nations born with a newly written Constitution. Let's consider the US Constitution and the British Conventions.
America's Constitution endures for five reasons:
it's susceptible to Amendment so it's a living document despite its absolute authority
it's kept in alignment with the Law by the Supreme Court whose job includes its protection and also its accessibility to the general public
It's extremely well written and wasn't handicapped by having to include leftover detritus from the system it replaced
at a time the enlightened world was actively engaged in formulating political systems, by founding fathers who were also de facto experts
it's retained continuity since coming into effect (i.e. America hasn't been conquered nor has their been a coup or revolution) which has allowed the Constitution to be mythologised in the minds of the citizens -along with the founding fathers - into a transcending national paradigm of both public and private ideals
Written constitutions are no panacea however. If anything, giving legal authority over 'everything' to a set of written rules simply focuses the attention of the unscrupulous end-justifies-means politicians and influential vested interests. The American system has inbuilt barriers to undermining the Constitution, not least the autonomy of the fifty state legislatures. A
Written constitutions end up having to stick to general principles so as not to devolve over time into mere rulesets, longer and more constraining than the Qu'ran.
Britain already has plenty of laws, conventions, precedents and formalised procedures. There's little to be gained from placing a static bunch of broad written principles over their heads. Nuance matters. Detail is essential for long-lasting consensus.
Also, abuses of power become harder to prevent when they're able to refer questions of legitimacy to an inflexible authority text.
It's worth looking at the full story of parliamentary function - not just the soundbites and the Commons front benches.
If there's a problem in the British political system, it's not going to be solved by nailing a list of commandments to the front door of the Houses of Parliament.