Thanks for everyones advice on this. I called up my local electrical
wholesalers (Newey & Eyre) and they recommended the cooker connection
option too, so I will go out and get one of those later on today. I am
a bit nervous about the earthing though. The hot & cold pipes are
cross-bonded at the base of the bath and I routed a cold supply pipe
under the bath and inside the opposite wall where the shower will be,
my understanding is that I just need to connect the earth terminal in
the shower to an earthing clamp on the new supply pipe. Is that
alright? Or am I going to cook myself (or the bird) when I first have
a shower? Also I had to use a little PTFE tape on some of the
compression joints because of some pesky leaks (under the bath -
nightmare), is that going to break the earth connection? Should I get
my hands on a multimeter and do a continuity test?

Thanks in advace,

Ross.