Andrew Mawson :
Nice bit of 100mm square box conduit (galv or pvc to choice) should
see you sorted. Half bury it in the wall, plaster up to it, and
incorporate it in your decor G

In a previous house I had the problem of getting quite a lot of wires
from the cellar to the first floor. The solution was to go up behind the
kitchen base units, then from the worktop up to the ceiling in square-
section white plastic fence post. Tucked into the corner, it looked
fine.

--
Mike Barnes