I normally do not care about down-votes and I still don't but for people who are downvoting me explain to me this: Where can I go and read the constitution that exists but that it is not written down anywhere? It's an oxymoron. So for all practical purposes there is no constitution.
It does, according to wikipedia (at least some sources are written):
> The UK does not have one specific constitutional document. Instead the constitution is found within a variety of written and some unwritten sources. This is sometimes referred to as an "unwritten" or uncodified constitution.