Long term street parking nuisance

[camresident]

For almost a year, a near-derelict dormobile has been parked opposite our house. It is not obstructing any entrance. It is taxed, but as a historic vehicle, so it has a disc but has paid nothing for it. It has been leaking oil onto the street for all that time, and is almost certainly undriveable (it also has no windscreen wiper!). Weeds are now growing under it! We have no way of knowing whether it is insured or has a current MOT.

Does anyone know if it is contravening any laws or parking regulations? and if so, which ones? and who can take action - police or local authority?

Any sensible suggestions as to how we get the wreck moved welcome!