Have had immense ongoing problems with a neighbour concerning planning permission for the last eighteen months and he has left us in no doubt that he intends to make our lives as difficult and costly as possible throughout the building process with constant monitoring, interference and phone calls to any relevant party who could possibly slow down our progress. His behaviour is at best obsessed and at worst, well I do wonder about MH issues. We have always been civil to him (despite extreme provocation) and our intentions are not underhanded in any way. My question is can we take legal action against him for interfering and causing us mental distress if he continues and carries out his plan to be as disruptive as possible? Where do I start?