It is common practice that if a defendant to a criminal or regulatory prosecution indicates their intention to plead guilty to charges, they will attempt to gain insight in to the likely sentence prior to formally entering the plea. In this case, four recent decisions have re-defined the prosecutor’s role in sentencing proceedings for both criminal and regulatory prosecutions. The practice of a criminal prosecutor offering submissions on sanction range at sentencing judge in this consideration, was redefined drastically in 2013 with the High Court of Australia’s decision in Barbaro v The Queen; Zirilli v The Queen  HCA 2. Since this time, Barbaro has been interpreted by R v Ogden  QCA 89, CMB v Attorney General for New South Wales  HCA 9 and Director, Fair Work Building Industry Inspectorate v Construction, Forestry, Mining and Energy Union  FCAFC 59, the latter of which has extended to applicability of Barbaro to regulatory prosecution practice.
The practical consequence is that these decisions have restricted the ability of a prosecutor to engage in negotiation between prosecutor and defendant where the defendant seeks to gain insight in to their likely penalty upon sentence.
WHAT DOES THIS MEAN FOR A PROSECUTOR?
Following these cases, the sentencing courts in criminal or regulatory prosecutions will no longer request or accept a submission from the prosecutor of an available sentencing range. Where one is agreed between the prosecutor and defendant, it will likely go only to demonstration of remorse, and other relevant considerations discussed below. The indeterminacy of agreed sanctions likely means that prosecutors will be more reluctant to offer a sentence range to a defendant without informing them of the effect of these decisions.
However, it remains the duty of the prosecutor to assist the court. The prosecutor should therefore as far as they are able without offending their guiding principles, do the following:
- Agree to factual matters with the defendant and present them to the court; 
- Agree to, or make submissions on, the application of the law to these factual matters; 
- Supply comparable sentencing decision transcripts to the defendant and the court;
- Make submissions regarding their factual similarity and seriousness in light of the agreed facts. 
WHAT DOES THIS MEAN FOR A DEFENDANT?
The most significant practical repercussion of these cases is that a defendant may no longer confidently rely on an agreement following plea bargaining with the prosecution. These decisions will create uncertainty for defendants when intending to plead guilty to prosecution matters.
Weighing against this disadvantage to a defendant are the following principles as relevant to sentence:
- The determination of the appropriate sentence is one that rests solely with the court;
- Any agreement or submissions on sentence by a prosecution (or as agreed between the prosecution and defence) is no more than an expression of opinion;
- There is no reason to divert from this view in regard to regulatory prosecution proceedings;
- The uncertainty created by these principles for defendants is an inevitable consequence of entrusting prosecutions to the judiciary.
In reality, where comparative sentences are provided by the prosecution, the defendant will have some idea as to a sentence which may be imposed, however as previously noted there will be some degree of uncertainty. A defendant will then make submissions at sentence regarding the timing of their plea, demonstrations of remorse and/or any evidence of assistance offered or given to the authorities which is in some way deserving of leniency. These submissions will be measured by the court against considerations of public interest and public perception of the judicial system. None of which have been altered by the recent decisions.