Thanks John.

There is no other bonding in the bathroom as all plumbing is plastic as it the bath.

Rather than a spur, I was going to break into ring on that floor and extend it to the bathroom. It is a bit of a pain as there isn't a straight forward way (that I can think of) to do it other than go to the nearest socket (bedroom across the landing) and split it there. Rather than have a junction box I was going to add an extra socket besides it to take feed back from the bathroom to rejoin the ring (if you see what I mean).

Will try and track down the installation manual for the bath and revert.

thanks again

Lee.