I /must/ have a room stat so the front room will be the rad without the
TRV,
the only issue now is the cable run through the kitchen and behind the
skirting. if it is low voltage I shouldn't have a problem with parts P & L

Well the good news is that it will be low voltage. The bad news is that it
will probably be 230V "low voltage".

is that right ? I'm only using a cheap £5.99 bimetallic room stat.

Seriously, throw away that w*nky bimetallic stat and fit a proper RF
programmable thermostat. It will be a fraction of the work and it will
probably earn its value back through optimum start and more accurate
control. You can also program it in the comfort of your living room, rather
than requiring a torch in a cupboard to an old style programmer. With an RF
stat, you can normally program it from your chair, as you can unclip it from
the wall.

Christian.