Saints, have you considered a non-NATS unit? Many such units still rely heavily on the Controller/Assistant working relationship, part of which make it such a interesting, varied and rewarding job.
From my experience, no previous ATC knowledge is needed, although I'm sure this will differ from unit to unit. Some aviation backround, whether it be working in the aviation industry, or having a PPL is beneficial.
My best advice is to get out there and let it be known that you want to become an ATSA. Go visit some towers, get to know people, make contacts, send your CV out...etc...if you make the effort, when an opportunity arises, you may well be in the forefront of their thoughts!
Best of Luck with it all.
Ps...its us assistants that
actually do the work and keep the tower running, we all know the muddles controllers get into without us...!
