Hi, could you confirm hat you have a documented right of way over the neighbouring land, in your Deeds?
Is your right set out in the deeds or is your right claimed by usage over a 20 year period?
If it is in the deeds, do you have a copy. I can review?
Are you asking how long you question will remain open? It will time out after a certain time but I am not sure how long.
I can say that because you have been exercising this right for over 20 years you have acquired what is known as a prescriptive right. This is a valid and legal right as if the right was formally stated on your deeds.
You (and others who also exercise this right, previous owner, neighbours) should contact a local solicitor to prepare a statutory declaration setting out what you have done and the length of time you have done it so that the new neighbour cannot deny or obstruct the right.