Sri Lankan
AKAfresh,
To get selected to the SL Airlines Cadet Pilot programme you do not need a A320 type rating. In fact they will provide you with a type rating as part of your cadet pilot training.
As far as hours are concerned, all that is required is a Sri Lankan CPL/IR and a Muliti Engine Rating. (i.e.your 235 hours will be sufficient) So you'll need to get your UK CPL converted to a SL CPL.
Having a British passport wont rule you out but NOT having a Sri Lankan passport will. Because you need to be a Sri Lankan citizen inorder to be eligible. So it would be a good idea to get your dual citizenship if you want to apply for Sri Lankan Airlines.
Hope this information was helpful...
Regards,
Sholva.