I agree. A fifty-something vote is more like "neutral" or "undecided" than "leave" or "remain". Perhaps 60% would be the clear threshold to count as a clear, un

I agree. A fifty-something vote is more like "neutral" or "undecided" than "leave" or "remain". Perhaps 60% would be the clear threshold to count as a clear, unambiguous decision from the voters to leave the EU. On the other hand, you don't want too high a threshold to make a change, like 3/4 to ratify, as js2 points out, because then you're effectively locked in to the status quo for too long. Another way of doing this is to offer voters a third option, "neutral/undecided". When counting, you'd treat these votes as if they were in favour of the status quo, remaining in the EU. Then, if 51% of the votes are to leave, Britain leaves the EU. After all, if you're neutral about something, you stick with what you have, rather than disrupting things for no good reason.