I thought this was because Britain didn't have a constitution as such so the don't have actual referendums?
> An actual binding referendum against a written constitution would have to provide actual wording; rather than just a single word.
I don't disagree for any philosophical reason, but this is very easy to abuse for anyone that favors the status quo. The most notable example I can think of is the republic referendum (to remove the queen as head of state) here in Australia. Deciding the form of the republic was done first and the constitutional changes to do just that was the only question put to the public, splitting the Republican vote.
On the other hand the EU has a bit of a reputation for voting until the plebs get it right, so I can definitely see the case for binding referendums.