Have spoken to the local council and 101 again, and have the following information to provide - please note it may only be relevant to this council (Hampshire).
1. The disabled bay is not enforceable. It is only a convenience bay, I think they called it. This is because there isn’t a sign post to state any terms/conditions, just the painting.
2. The council can’t/wont do anything, as they consider it a police matter.
3. The police can’t/wont do anything as they consider it a council matter, with it being on public highway.
I asked the police officer whether technically, the two cars could remain parked there indefinitely, rendering the car unusable for the equivalent amount of time. They said yes.
In their view, parking and blocking you in is not illegal on the public highway, it would only be so if they blocked you in your property.
Essentially, nothing I can do at this stage. Guess the car is staying there, which will annoy them more that it will me/my mum