Residents’ Only Parking Schemes are intended to stop residents from competing with motorists from outside their locale from taking parking spaces that are briefly supply. But as you’ve got came upon, the enemy from outside the realm is usually not as pernicious because the enemy inside, as near neighbours compete with one another for the parking spaces restricted to them only.
There are different rules about parking on the general public highway, versus land which is in private ownership. Private businesses can exercise full authority over what happens on land under their control, including parking arrangements for supermarkets, cinemas, hospitals, railway stations and gymnasiums.
Private parking schemes also arise on some residential developments, akin to purpose-built flats where a management company oversees the “common parts” of the event. In these examples, it might be possible for the landowner to ban campervans.
From what you say, your situation is not one of the above in that you just appear to continue to exist a residential street which abuts the general public highway.
You say your own home is Victorian, so it’s unlikely there will likely be a so-called covenant on the land to limit parking of huge vehicles outside your own home. Almost definitely, parking outside your own home will likely be as per the same old rules as to parking on the general public highway, which is permitted for anyone unless it’s restricted not directly – akin to by double yellow lines, other road markings like zigzags, or restricted for another stated reason.
In your street what I surmise has happened is the local authority (hopefully after consultation with residents) has introduced a Traffic Regulation Order under The Road Traffic Regulations Act 1984 to define who can and can’t park on the general public highway in your neighbourhood. It’s like having double yellow lines, but ones which you and your neighbours can ignore, but which apply to everyone else.
I say all this because it will be significant to grasp the legal status of the road outside your own home and the way that status impacts on who can park there and on what basis they’ll park. A residents’ permit scheme means any resident with a permit can treat the road similar to the general public highway and park where they like, including in front of your own home.
Yes, your neighbours are being selfish by not parking their massive campervan outside their very own house, but it surely is perhaps difficult to say they’re acting unlawfully.
Except that the residents’ only parking is a scheme managed by the local authority, and that does offer you potential leverage in that you’ve got a body with direct oversight they’re actively managing. The important thing here is the principles of the scheme itself and the broader duties of the local authority.
Each local authority may have barely different rules, and I suggest you study yours rigorously. There is perhaps a restriction on not using the visitor permits for a similar vehicle for greater than an outlined period, or for the scheme not for use for a vehicle over a certain height or weight. You possibly can go surfing and check the peak and weight of the make and model of the offending campervan and see whether it is in breach or not.
What’s more, while your slightly thoughtless neighbours could also be operating inside the principles of the scheme, it seems they should not behaving morally – and which may be where getting your local elected councillor on side may help. Complaining that you’re feeling the residents’ parking is being “exploited” and asking for a review of the scheme, including use of visitor permits may help your cause. On the very least your local councillor may go to talk to your neighbours and check out to broker a deal.