Struggling to choose the correct forms

Hello, I need some help if anyone is able.

I need to figure out which form is the best to protect a right of access/prevent building on a right of access.

For context, the access is a pathway leading through a row of terraces, it has been in use for over 100 years, and is still used to this day. Recently a neighbour has applied for planning permission to build on this right of access essentially blocking it off.

The pathway is private land, however is communally owned by the row, and is unhighlighted on everyone's deeds. My deeds specifically mention a right to pass and repass, and I also have copies of the neighbours title plan and original deeds confirming that it is unhighlighted and not owned by them also (however they are claiming to own it)

I do not wish to claim the land, just to prevent the right of access being restricted or blocked. If anyone could point me in the right direction I'd really appreciate it.

Hello Christina - there is no such HMLR form. If the right is registered then it is protected.
It's the planning process you need to focus on here and any opportunity to object to plans to build over the access. The plannign process is very separate from the registration process.

Hi Adam

Thank you for your reply. All the planning objects etc have been done.

It's a bit of a tricky one with the land (ive maybe posted in the wrong forum) but initially I thought it was maybe a UN1 form or RX1 that we needed. To basically put a formal "notice" on the land. The right in the deeds, but the neighbour is denying this, so im basically looking for anything that might give a bit of extra protection. An injunction will be taken out if necessary.

Christina - if you are looking to 'protect' the right of access, as it's not on the actual title over which it has been granted/created then the best option is to get legal advice
Yes third parties can seek to protect certain interests using forms UN1 or RX1 but they are not generally for the protection of actual rights (easements) - Notices, restrictions and protection of third-party interests (PG19) - GOV.UK
Easements are something else and our PGs 52 and 62 explain more re how they might be claimed and noted  and/or granted/reserved and registered against both the benefiting and subjective land as appropriate 
Easements claimed by prescription (PG52) - GOV.UK and 
Easements (PG62) - GOV.UK
However it reads very much as if this is something to pursue through the planning process and/or legal action as you suggest. You already have the 'right' registered in some way so it's more a Q of ensuring that is then protected so as to stop anyone denying you that right. 
Legal advice would certainly be the 'best' next option here 

Thank you Adam for your help. I'll look at the links. :)