Brian,
The Bear is quite right, and it's very important that you approach the problem in the right manner, until not so long ago I used to review such applications on a regular basis, and you wouldn't believe some of the expectations that were expressed.
At the moment, there are many people in your situation, and their's more chance of Red Rum winning next year's London Marathon than being taken on as a student/trainee atco, so I strongly suggest that when you apply, you emphasise that you are looking to be employed as an Air Traffic Assistant initially, with an ambition to progress within the unit.
I suggest that you telephone each unit Air Traffic Services Manager - be persistant but not pushy in wanting to talk to them - then immediately follow up the call with a CV to them.
You're not alone, and the competition is very strong - but if you can find somewhere to go, keep your head down and work hard, you'll get what you want out of it.
If you want further info, PM me.