Neighbours patio causing flooding in our garden

Yes, but you can try to get someone from the council come round if you make it sound serious.

But, why on earth would someone have a porcelain patio ? That should be slippery most of the year thanks to our lovely weather!

I'm not sure the council will act if its rain water. The best option is for him to trim the edge off and install a French drain in to a soak away. Your claim for damages would be the cost of doing the same on your land. Plus I think you can then bill him for the rental of your drain, a way leave surveyor will be able to advise.

It would go something like this:
- serve formal notice of the nuisance and the damages that will be due if not rectified.
- claim in the county court for the cost of installing the soak away on your land.
- bill him for the rental annually.

A photo would help people make more suggestions.
Especially a photo showing the boundary and edge of the patio where the water flows.