Sponsorship does not really exist anymore. There are a few schemes around that give you a conditional employent based on acceptable performance throughout your training but they generally tend to require similar financial arrangements up front to cover the liability so a sizable loan/ access to considerable funds is required. Oxford Aviation Training do a couple of schemes (NetJets, Thomas Cook and Excel) but these cost about £75k, Flight Training Europe have a couple of mentored schemes which again offer a very conditional training offer if you perform satisfactorily (GB Airways, Flybe) for about £65k and CTC Wings offer a cadet scheme that works in partnership with a number of airlines that puts you into a job on a reduced salary for a few years while the airline pays back your loan (British Airways, easyJet, First Choice, TUI Airlines, Thomas Cook, Monarch, Jet2) for £60k. Selection for all of these is tough and it gets pretty competitive.
There are a few other schemes around but your best bet is to use the search function - there are thousands of threads on here that will serve you well I am sure!