SERCO tend to ask for at least five years experience, any flexibility depends on the customers' requirement. I know that they've been pretty rigid on this requirement in the past, but I don't know if things have changed.
One very big question they will ask, and they'll want a convincing answer, is why you want to leave your present employer after only 2 years, and what assurances they have that you'll not do the same to them in the future.
Anyway, best of luck.