This is one of most common charges I represent people on.
The broad outline is this:
The legal level for an adult is 400mg / litre of breath.
400-650 is a low to moderate reading.
650-1000 is a moderate to high reading and you will be suspended for driving for 28 days on the spot - you are not credited with this time if you are disqualified on the charge, nor does it apply towards a 28 day stand down period for a limited licence.
Over 1000 is a high reading and you are in serious trouble.
FAQ on the process:
Will I be convicted?
If you plead not guilty and win then no. There are limited defences for drink driving but they exist and if available should be pursued.
If you plead guilty - You cannot get diversion for drink driving. However you may apply for a discharge without conviction which is granted very rarely.
Will I lose my licence?
There is a mandatory disqualification period for a minimum of 6 months on drink driving - and 1 year and 1 day if it is your 3rd or subsequent.
You may be eligible for a work licence or limited licence, community work in lieu of disqualification, or special reasons not to disqualify.
What am I looking at?
Roughly - first time fine, second time community work, third time electronic sentence or prison, above 3 prison is always on the table. Note: This is a very rough idea and your personal circumstances, other factors in the case, drink drive history etc.. may very well affect this.
I've represented 1000's of people on drink drive charges as a duty lawyer and counsel. If you would like to discuss your case feel free to get in touch, please have your paperwork handy.