With the majority of driving offences there can be mitigating circumstances that may lead to some leniancy but as far as I know when you get done for DD it is always a ban and you will be in court within days of the offence happening.
You will not be prosecuted if you are under 39mg...between 39 and 50 you have to be offered the chance to replace your breath specimen with blood or urine (the choice of which being the police officer's). Anything over that, you've had it I'm afraid...