Feeding wire to spur socket

[Toppops]

I'm trying to install a socket under my desk ,the desk has an old rad at the back which is no longer used and built in shelving on top of the desk. On top of that is the double socket I want to spur off of. The top socket is fed through the gap behind the old rad, I have made a new hole in the pattress box to feed a new length of 2.5mm t&e down to feed the spur, although it only goes down so far then stops. The hole is too narrow and there is limited space to guide it down using fishtape. I'm not sure if it's hitting something at the back or what's going on as the rad is in the way to see anything, I'm not sure if I would be better to remove the top pattress box, although I don't think it's that which is stopping the cable going all the way down. Any ideas?

 

[EFLImpudence]

Plasterboard wall?

Noggin? Dot and dab?

 

[Toppops]

Plasterboard wall?

Noggin? Dot and dab?

The wall is brick. I should probably say it's a surface mounted cable that is fixed to the wall behind the rad

 

[sparkwright]

Small chain on a piece of string to use as a draw wire?

Don't know if we like cables going behind radiators, working or otherwise, but there you go.

 

[ban-all-sheds]

the desk has an old rad at the back which is no longer used
.
.
Any ideas?

Remove the old radiator.

 

[Toppops]

Small chain on a piece of string to use as a draw wire?

Don't know if we like cables going behind radiators, working or otherwise, but there you go.

I know it's not ideal, however the cable has been there years to my knowledge, even when the radiator was used and I don't think any harm has come to it.

Remove the old radiator.

It's out the question unfortunately, as the desk is large and would need dismantling plus it's screwed to the wall.

After much fiddling I attached some earth sleeving to the end with some insulation tape and managed to pull it down. I had to go in closer to the right side and draw it across, think it was hitting a fixing for the shelf or rad bracket. Thank you .