Maybe I'm a bit naive in current situations, but surely, if they've taken a deposit, in effect, the property's yours. Last I heard, agents cannot now charge fees to lessees (except for some admin.)
It's based on whether my application is given the OK, if for whatever reason I get turned down by them or the landlord then they refund it, if I get the green light it is taken off the first months rent.
Don't ask me Mike, I'm just a pleb playing the game, I jump when they say so and fill the forms in.