In reply to IainRUK:
Thanks, my Dad would be ashamed of me, but I can never remember, he would have said "6 to 1 on" in this case. So at least the bookies, or their punters anyway, think the no is favourite, which I find reassuring.
On the other hand I'm amazed to see campaigning going on right up to the voting places (got it right this time), in France this is completely banned and would lead to a revote. On the other hand revoting a referendum is a bit heavy.