It occurs to me that with the removal of the need to display a current tax disk, I don't think you can assume a vehicle is untaxed. It could also be declared off road (i.e SORN). And I do not know how anyone other than the police, and insurance companies can determine if it's insured.
If it is SORN, then it means the vehicle shouldn't be on the public highway, and it doesn't have to be insured. This raises the question if road is a public highway or privately owned. If it's privately owned, the police have no mandate to be involved and no offence has been committed.
If the road is a public highway, then the vehicle might classed as causing an obstruction, preventing legitimate access to an adjoining property.
If it is SORN, then it means the vehicle shouldn't be on the public highway, and it doesn't have to be insured. This raises the question if road is a public highway or privately owned. If it's privately owned, the police have no mandate to be involved and no offence has been committed.
If the road is a public highway, then the vehicle might classed as causing an obstruction, preventing legitimate access to an adjoining property.