As Jack says, many residential estates built since the 1970s (I.e. when the growth exponential growth in mobile touring caravan ownership started) will have covenant as part of the land registry title that prevents this sort of thing being dumped on the driveway. This will have been a condition on granting planning consent by the local authority on the developer, who is then obliged to transfer the restriction onto the original purchaser. It then gets transferred on.
The trouble is the original developer is not interested in enforcing the original covenent, but the local authority may be interested.
If you and your neighbour have no such restriction, I doubt you can do anything. The right to light cannot apply to a temporary structure, which this effectively.
You can try for a second opinion from CAB, but in most cases my knowledge of this sort of thing equals CAB.