Right of way over private car park

[Funloving]

Hi, would appreciate some advice if anyone knows about property law? This might be difficult to describe, but will give it my best shot. Sorry if it gets long.

We bought a house that is adjacent to a car park of a block of flats that is owned by a housing association. We own two parking spaces at the end of the carpark, immediately alongside the wall of our house. It is a long thin strip, and the cars go one in front of the other IYSWIM. The car park itself is not massive, and can hold about 15 cars other than ours. When the flats were bought by a housing association (not the one that owns it now), they bought some land from the previous owners of our house to make the car park bigger and level it, and in so doing, the access to our carparking spaces changed from being directly from the road to being through the carpark. There is a document in our deeds surrounding this (an easement?) that states we have full right of way across the car park for all domestic purposes.

So the problem: one of the tenants in the flats owns a (massive) camper van that he absolutely insists on parking in the space immediately adjacent to our spaces. He has permission to park the van in the carpark, but they don't have designated spaces. In doing so, he makes it so much harder to get in and out of the spaces in our cars (we have an MPV and an estate), and there isn't much room to swing round. He makes it impossible to get a larger vehicle such as a van in. He argues that because we can use it, it's not a problem, and we should just learn to drive better (he's not very nice).

We have approached the housing association - they were initially sympathetic, and got him to sign something to say he would park a space further down. However, 3 weeks on, nothing had changed. I phoned them and then yesterday we received a letter from the HA saying that although they apologise for the inconvenience to us, he has permission to park his van in the carpark, and if he parks it anywhere else he will block access to other tenants so there is nothing they can do. Even though that acknowledges that he is blocking access for us.

So... A couple of specific queries:

1. Does this constitute an infrigement of our right of way even though technically on a good day we can get in to our spaces in certain vehicles?
2. Is the HA right that there is 'nothing they can do'? Can they not revoke permission/change the tenancy agreement/end the tenancy agreement?
3. If we did take legal action, would it be against the HA or against the tenant?

Hope I've made some sense. Sorry it's long. Thanks for any help!

Not a property lawyer, but here goes:

You have a right of way for all domestic purposes. If the HA says that him parking anywhere blocks access to others, are the implicitly accepting that he blocks access to your space? If so, I would guess that you have a claim.

I would have thought that because it's domestic purposes, you may be limited in the type of vehicle you can park there (so no commercial vehicles).

I suspect you'd enforce the easement against the landowner.

Hopefully someone who knows a lot more than me might come along soon.