TOPIC:

So the 12v socket for the back passengers is definitely out (the one on the back of the centre console)

Does anyone know which fuse is likely to have blown as a first port of call?

cheers
Gary 

I think there is a dedicated fuse for the front and back sockets  Check handbook under fuses which in 2017 version I have just looked at is 5.24 - 5.27 I think

thanks, I will have a look.

if it is a shared fuse though then something else is up, as the front one works

Just to confirm as folks have thought this before, power to the socket does time out shortly after stopping the engine.

thanks, yes, have seen that (but good to have it on record on the new forum)

this socket is out whilst driving the car along, and the front one is still live

Looking in the manual there will be a list of what fuse does what when I open the access panels, so hopefully when I get 5 minutes at the weekend I can find it easy

In that case I would suspect the socket itself of the wiring somewhere down the line rather than a fuse. I cannot imagine or recall the 2 sockets being on separate fuses.