Bear laid this down on his screen :
Despite having two large external air vents
in the wall on one side of the wardrobe,

Which is the cause of your problem.

I'm suffering from damp
problems (mould on the wall, and damp wet feeling transferring from
the wall to the clothes).

Warm air in the house is getting into the cold wardrobe and condensing.
The wardrobe needs the vents diverted to either vent directly into the
room, or blocked off, but either way the wardrobe need more ventilation
from the warmth of the room to bring it to the same temperature.

Another way would be to add some form of heating in there - maybe a
loop of pipe from the heating system passing through it would be
enough.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk