Thanks all for the replies. Yes current owners have horses in there, although previous didn't - currently they are in a paddock and not allowed up to the inner fence (its falling apart). We did try to buy the strip between the fences from the previous owners but it fell through when they decided to sell up; hopefully when new owners have settled a bit more we can broach the subject again. Again, I hope we can reach an agreement on how to manage going forward , we don't mind cutting it back if needs be. No-one has mentioned the "legal right to have 1m clear" that my neighbour believes is the case though, so I'm going to assume that's a myth - at least from the point of view that I can go in and clear it myself - which makes sense to me - if done without permission then surely trespass.