Just putting in a fused spur off the ring main - only 6 inches away from existing double socket Carefully removed plaster next to double socket - all clear. Marked the position of new backbox for fused switch. Drilled a honeycomb of holes where back box to go. When I started chipping plaster out - I found that a diagonal 6mm cable for the cooker ran straight through where the box was to go. I had actually drilled through the T&E - a perfect hole straight through - it had not tripped RCD or fuse.
Question: The cooker was recently wired in as part of a kitchen upgrade : are diagonal runs permitted under the relevant regs?