There is something to be said for your written constitution though: having the fundamental principles on which your nation is founded enshrined in that way should, at least in theory, make it a lot easier to settle arguments (though in practice, and particularly recently, that does seem not to be the case). Constitutional wrangling in the UK is always really fraught though because it's all done by precedent and is therefore incredibly hard work to get to a clear understanding of what the situation really is.