If this is on private land, neither the police nor the local authority have any say whatsoever and it comes down to the landlord or the management company to enforce it.
Sometimes that is enforced using private parking companies and supermarkets typically do that as do management companies of blocks of flats.
If it is a public car park or space, the police will not normally get involved and it is enforced by the local authority.
There are various bylaws and of course the Highways act & Road Traffic.
Who enforces it depends on whether it’s private land or public. Just because the public have access to it doesn’t necessarily mean that its public land.
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