Ask an Property Solicitor. Get an Answer ASAP.
I have been asked to look at this for you.
I you able to let me have a plan with some narrative please?
Do you have any photographs?
Is the work that you required to do necessary because of any action or works which have been done by the neighbour? If it is, then you have a claim against the neighbour in common law negligence and potentially also common law nuisance.