Cables (including power) in chimney breast

Hi all

I appreciate that there are a few threads that touch on this within the content of such things as whether it is viable to put screens above fireplaces but I wanted to ask the question outright.

I am hoping my installation should be quite simple as I have an understairs cupboard between the chimney breast in the family room that I am planning on putting the LCD onto and a separate chimney breast in the lounge that I could well be putting another screen onto (see attachment).

Both of these fireplaces are working real fires

I am planning on putting all my AV equipment under the stairs and I have ample power points in there to feed the TVs and AV equipment.

My question is whether I can run the cables from the TVs straight through the wall behind them into the understairs cupboard as it would be so much tidier and easier to do this rather than channelling out the L of the chimney breasts and going through the walls to the side of the chimneys.

If I can do this I am presuming that I would need to protect the cables from fire/heat damage by putting them in some kind of ducting/conduit? If so, do you have any suggestions as to what product to use?