Your best bet is through an agency. Try Premier Work Support, based in Voyager House at Manchester airport.
You won't get the cream of the crop, by a long way, but once you're in you hear about other positions much easier than you do if you're not currently working there.
Try
Jobs, vacancies in Manchester Airport | Indeed.co.uk
Or
http://www.totaljobs.com/JobSearch/Results.aspx?Keywords=&Sort=2<xt=Manchester+Airport&Radius=0
I got in by using these methods, so there's always a way. Good luck!