I decided to respond before reading anyone else's opinion.
In general, down through the centuries the lack of a written Constitution seems to have served us well, because most executives have respected tradition. However Tony Blair is working fast to dismantle a system that has worked well for longer than pretty much anyone else's system, and there are no formal rules to stop him from doing that. Important new law goes through without parliamentary debate. The executive reigns undreamed, the House of Lords has been emasculated without being replaced with anything (in the name of fairness). We're getting close to an elected dictatorship (elected by less than a quarter of those eligible to vote). New administrative regions are created that no-one identifies with or cares about. Expensive new elected assemblies were set up for Wales and Scotland, yet Welsh and Scottish Westminster MPs still get to vote in Westminster on matters that don't affect their constituencies because those matters are controlled by the new assemblies. The government wouldn't dare contemplate self-rule for England though, of course, because an English assembly probably wouldn't be suitably socialist. Rant done.
True.. but England(Wales, Scotland even Ireland) will be a mere State(s) in the World Republic.. eventually... so will the U.S.... in the new world order..
But the respected traditional culture has been increasingly, progessively trashed by the invidious thugs of mindless Left progressivism, and also by Islamofascist thugs these days. It appears the two work hand-in-hand, on the theory "the enemy of my enemy is my friend." The apparent result is the firm foundation for a just rule of law is being corrupted, eroded, destroyed....
We have the same problem over on our side of the Pond. In recent times, the Constitution itself has been placed under grievous stress by people who choose to read their own novel meanings into the text, eschewing totally the Framers' original intent and meaning, which has been the foundation of our settled law for some two centuries.
Plus like us, you have an immigration problem -- e.g., lots of poor, low-skilled people of different ethnicity who come into the country, and then refuse to acculturate -- that is getting totally out of control. Your unassimilables want Englishmen tried in sharia courts. Our unassimilables recently translated our national anthem into Spanish, rewriting it and changing its meaning in the process. The French and Dutch and Danes can report similar miseries.
Sigh, we do live in interesting times....
Thank you so much for your report from the British Isles, Thatcherite! Very much appreciated.