My other half is a pilot and admits that recruitment is poor or non-existent at the moment, but should improve soon (and probably by the time people have finished their frozen ATPL courses).
dunelmitepilot: beware at future stages (especially Stage 2) if you pass the selection tests - there are a few questions about ambitions within aviation in general, are you a planespotter, do you want to become a pilot, etc - I got the impression that they seem to be trying to weed out those who are considering ATC because pilot stuff isn't going very well at the moment.
I'm definitely not trying to dissuade you from your NATS application, but be sure that this is really what you want to do - the interviewers seem to want to see long term enthusiasm and commitment to an ATC career, not just any career in aviation.
Good luck with Stage 1 when it comes around!