I was interested in becoming an ATCO but had been rejected once by NATS so wrote to every (non-NATS) airport in the country to see what they had going. That resulted in being taken on as a Flight Briefing Assistant with SERCo, which led to an ATSA position at the same airport. Then I applied again to NATS and got in, thanks in no small part to my experience and determination. Am now an ATCO at a London Airport. Never give up and be prepared to work anywhere in aviation, if you want it that badly. Being an ATSA is great - you get all the perks of the job except the money, but none of the stress!