R. v. Gill, 2012 ONCA 607 deals with mandatory minimum sentences for impaired driving offences. Such mandatory minimums increase with prior convictions. But for the minimums to apply the prosecutor must decide to give notice of the prior convictions - it is common for prosecutors to not give such notice with the intention of not triggering the minimums. Today's decision makes it clear such discretion, while subject on rare occasions to review by the Court, is not normally subject to such review on a reasonableness standard:
 It seems to me that counsel for the appellant's characterization of the prosecutor's decision to prove the notice as an exercise of core prosecutorial powers is more a reflection of the nature of the impact of the decision on the accused rather than the nature of the decision itself. In almost any case, the prosecutor will have to decide what evidence to lead on sentence. This will include evidence of potentially aggravating factors. Some aggravating factors are specifically identified in the Criminal Code. For example, s. 718.2 identifies several circumstances that must be taken as aggravating if proved by the Crown. The Crown has a discretion as to whether to lead evidence of the facts referred to in s. 718.2. on sentencing. I do not think it could be argued that the prosecutor, in electing to prove a s. 718.2 aggravating factor, e.g. racial bias, was engaged in the exercise of a core element of prosecutorial discretion. The Crown's decision to prove the notice is qualitatively no different than its decision to prove other aggravating factors on sentence. The nature of the decision does not change because the notice triggers a minimum penalty whereas proof of other aggravating factors does not. A decision to prove an aggravating fact on sentence, regardless of its impact on the range of available sentencing decisions, is a litigation decision made in the prosecutor's exercise of his or her discretion concerning the conduct of the proceedings on behalf of the Crown.
(iv) The Relevant Principles of Fundamental Justice
 The distinction between prosecutorial decisions that engage the core prosecutorial discretion and other prosecutorial decisions is important because the former are reviewable only for abuse of process. Thus, if an accused challenges a prosecutorial exercise of discretion under s. 7 of the Charter, and that decision is said to go to the core prosecutorial power, it can offend the principles of fundamental justice only if it constitutes an abuse of process. Put in a more positive way, prosecutorial independence, itself a principle of fundamental justice, forecloses judicial review of core decisions under s. 7 for anything other than abuse of process.
 My conclusion that the Crown's decision to prove the notice is not an exercise of a core element of prosecutorial discretion means that the principles of fundamental justice do not limit the review of the prosecutor's discretion to allegations of an abuse of process. The question then becomes what is the appropriate scope of review under s. 7 for prosecutorial decisions that do not reflect the exercise of that core prosecutorial discretion. To answer that question, one must identify the applicable principles of fundamental justice.
 The principles of fundamental justice refer to those legal principles that are basic to, and vital to, our notion of criminal justice: Rodriguez v. British Columbia (Attorney General),  3 S.C.R. 519, at paras. 141-146; Mohla, at para. 175. The applicable principles of fundamental justice will depend on the context. A prosecutor's decision to prove the notice will run contrary to these principles of fundamental justice and, therefore, violate an accused's s. 7 rights if it:
· undermines the integrity of the administration of justice;
· operates in a manner that renders the sentencing proceedings fundamentally unfair;
· is arbitrary; or
· results in a limit on the accused's liberty that is grossly disproportionate to the state interest in proving the notice.
 Although the decision to prove the notice is not an exercise of core prosecutorial discretion, the exercise of that discretion is subject to review under the abuse of process doctrine. A decision to prove the notice that constitutes an abuse of process will result in an infringement of the liberty interest of an accused that is contrary to the principles of fundamental justice.
 Abuse of process in the context of challenges to the exercise of prosecutorial discretion refers to decisions that either undermine the integrity of the criminal justice system in a broad sense, or fundamentally impair the fairness of the specific proceedings: Nixon, at paras. 36-42. I need not attempt a more exact description of the first category of abuse of process as it is not suggested that the Crown's decision to prove the notice in this case could somehow undermine the integrity of the criminal justice system.
 The second category of abuse of process looks at the impact of the exercise of the prosecutorial discretion on the right to a fair trial. That right extends to the sentencing process. Fairness is generally assured by compliance with the applicable procedural and evidentiary rules. Section 7 remains available, however, if despite compliance with those rules, the proceeding is rendered fundamentally unfair to an accused as a result of challenged prosecutorial conduct: R. v. Albright,  2 S.C.R. 383, at pp. 395-396.
 Trial fairness is a procedural concept. Trial fairness speaks to things such as proper notice to an accused of the case to be met and a fair opportunity to meet that case. Trial fairness does not mean that the prosecutor must make decisions that the court considers to be reasonable. Trial fairness is also not concerned with the trial judge's notions of the suitability of a minimum penalty that may arise as a consequence of a decision made by the Crown. Assuming the minimum penalty is constitutional, and no one suggests that the minimum penalties in issue here are unconstitutional, exposure to those penalties is not unfair in any relevant constitutional sense. The prosecutor's decision to prove the notice did not cause any unfairness to the respondent.
 Arbitrariness, a well recognized principle of fundamental justice, also applies to the exercise of prosecutorial discretion: see PHS Community Services Society, at paras. 126-132. A decision will be arbitrary and contrary to the principles of fundamental justice if the decision bears no relationship to the objective of the relevant legislation: Canada (A.G.) v. Bedford, 2012 ONCA 186, 109 O.R. (3d) 1, at paras. 143-147. The relevant law for present purposes is s. 255 of the Criminal Code, which provides for minimum jail terms for second and subsequent drinking and driving offences.
 The objective of the sentencing regime established under s. 255 is obvious. The mandatory minimum jail terms for second and subsequent drinking and driving offences speak to Parliament's resolve to reflect the community's denunciation of conduct that is both inherently dangerous and one of Canada's most pressing social problems. The statutory regime further demonstrates Parliament's determination to deter the repetition of that conduct by the promise of certain incarceration.
 Service of the notice by the prosecutor, a precondition to a triggering of the mandatory minimum jail term, is consistent with and bears a direct relationship to the achievement of the legislative objective underlying s. 255. Without the notice, Parliament's promise of incarceration for repeat offenders cannot be kept. Arguably it is where the prosecutor decides not to prove the notice that the exercise of prosecutorial discretion conflicts with the legislative objective of s. 255. However, the arbitrariness of that decision is constitutionally irrelevant as s. 7 is not engaged when the prosecutor chooses not to prove the notice.
 I think the policy enunciated by the Attorney General in the Memorandum is also relevant to the arbitrariness inquiry under s. 7. A decision by an individual prosecutor that bears no relationship to the objectives underlying the policy in the Memorandum would, in my view, be arbitrary and contrary to the principles of fundamental justice. The policy clearly calls for an exercise of discretion based on the mitigating and aggravating factors of the specific case. The policy also draws a distinction between prior offences that occurred more than five years before the latest offence and those that occurred within five years of the latest offence. Thus, for example, if a prosecutor took the position that the notice must be proved in all cases, or that the passage of more than five years since the last conviction was irrelevant, the prosecutor's decision to prove the notice would bear no relationship to the objectives of the policy and would be arbitrary and contrary to the principles of fundamental justice.
 The arbitrariness inquiry based on the Attorney General's policy does not, however, contemplate a review, on any standard, of the merits of the prosecutor's decision. A decision to prove the notice predicated on both a recognition of the discretion, and an assessment of the mitigating and aggravating factors is consistent with the objectives of the Attorney General, regardless of how the discretion is exercised.
 On this record, it cannot be said that the prosecutor's decision to prove the notice bore no relationship to the objectives of the policy set out in the Memorandum. The prosecutor was clearly alert to the policy and the significance of the time gap between the prior convictions and the conviction for which the respondent was being sentenced. The prosecutor also appreciated that the number of prior convictions, a clearly aggravating factor, was relevant to the exercise of his discretion.
 It is important to bear in mind that it was not for the prosecutor to prove that he did not act arbitrarily. It was incumbent on the respondent to establish a breach of s. 7 by demonstrating arbitrariness in the sense that the prosecutor's decision bore no relationship to the objectives of the policy. The record offers no support for that assertion.
 Gross disproportionality is also a well established principle of fundamental justice. If the deprivation of liberty occasioned by the exercise of the prosecutor's discretion is so extreme as to be clearly disproportionate to any legitimate government interest furthered by the exercise of the prosecutor's discretion, the prosecutor's conduct will contravene the principles of fundamental justice enshrined in s. 7: see Bedford, at para. 149.
 The deprivation of the respondent's liberty interests occasioned by the Crown's exercise of its discretion to prove the notice flows from the mandatory minimum penalties prescribed in s. 255. Arguments alleging gross disproportionality in respect of sentences are addressed under s. 12 of theCharter. A sentence that passes constitutional scrutiny under s. 12 cannot be found to offend the gross disproportionality principles of fundamental justice: R. v. Malmo-Levine, 2003 SCC 74,  3 S.C.R. 571, at paras. 159-162. The respondent has not argued that the minimum sentences are so grossly disproportionate as to contravene s. 12. This concession effectively defeats any s. 7 claim based on gross disproportionality.
 The trial judge did not refer to the principles of fundamental justice discussed above. Instead, after holding that proof of the notice was not a core prosecutorial function, the trial judge concluded that the court could require the prosecutor to "justify" his decision to prove the notice. At para. 50, the trial judge held that the court could review the justification offered by the prosecutor:
to determine whether the Crown acted reasonably and took into account only appropriate considerations in making its decision. If not, the decision to file the notice would be set aside.
 Putting the trial judge's findings in the framework of a s. 7 analysis, I take him to have held that the principles of fundamental justice require that the Crown offer an explanation for the exercise of the discretion to prove the notice and that the exercise of that discretion can survive s. 7 scrutiny only if the trial judge views the exercise of discretion as reasonable. I think the Summary Conviction Appeal Court effectively adopted the same analysis: see paras. 57-58, 67-68.
 I cannot accept this analysis. There is no freestanding principle of fundamental justice requiring that the Crown justify the exercise of its discretion to the trial court. To the contrary, our legal tradition – the source of the principles of fundamental justice – has long recognized that the independence of the prosecutor and the very distinct roles assigned to judges and prosecutors in the criminal process combine to dictate that judges should not oversee trial decisions made in the exercise of prosecutorial discretion except to the extent that they impact on the integrity of the process or the fairness of the trial. To require prosecutors to "justify" decisions to trial judges on a reasonableness standard is to imply that trial judges have some sort of supervisory role over the conduct of the prosecution. They do not. Further, to open all prosecutorial decisions that impact on an accused's liberty to a reasonableness review by the trial judge could significantly prolong criminal proceedings and add yet a further layer of motions and applications to what has become an ever more complicated and protracted process: see R. v. Power,  1 S.C.R. 601, at pp. 626-627;Nixon, at para. 52; and Michael Code "Judicial Review of Prosecutorial Decisions: A Short History of Costs and Benefits, in Response to Justice Rosenberg" (2009) 34 Queen's L.J. 863, at pp. 883-885.
 I do not mean to suggest that the prosecutor may never be required to explain its decision to prove the notice. If the accused, who carries the burden of persuasion on a s. 7 application, leads evidence of a violation of s. 7, the Crown must respond to that evidence. In doing so, it may be necessary to offer an explanation for its decision to prove the notice or face an adverse finding based on the evidence offered by the accused.
 I also do not intend to discourage the prosecutor from offering an explanation for its decision to prove the notice in those cases where that decision is not self-evident. By offering an explanation, the prosecutor clearly enhances the transparency of his or her decision making process and, hence, the fairness of the proceeding. Those positive consequences are a good reason for the prosecutor to offer an explanation. Those consequences do not, however, justify the conclusion that an explanation is constitutionally demanded by the Charter. In my view, the prosecutor is under no constitutional obligation to give reasons for the decision to prove the notice.
 I also cannot agree with the trial judge that the principles of fundamental justice require that a trial judge review the exercise of the Crown's discretion on a reasonableness standard. In selecting reasonableness as the standard against which to review the prosecutor's decision, the trial judge said at para. 51:
Most discretionary powers and decisions are reviewed on the basis of reasonableness. Courts are well equipped to assess whether the decision maker turned its mind to appropriate considerations and whether the decision was unreasonable.
 With respect, there are two errors in the trial judge's observation. First, the common practice of reviewing the exercise of discretionary powers on a reasonableness standard involves reviews that are based on the statutory grant of a power of appeal or judicial review. There is no such statutory authority for review of a prosecutor's exercise of his or her discretion. The review the trial judge conducted was not premised on any statutory authority, but rather on ss. 7 and 24(1) of the Charter. I am unaware of any authority that has held that reasonableness is a principle of fundamental justice against which state conduct that limits liberty can be measured.
 Second, I must disagree with the trial judge's indication that the courts are "well equipped" to assess the reasonableness of the prosecutor's exercise of his or her discretion. The deference traditionally shown by the courts to all prosecutorial decision making is founded on the recognition that the distinct roles played by the prosecutor and the judge, combined with practical institutional limitations, make judicial review of the exercise of prosecutorial discretion very difficult.
 This case demonstrates how easily a reasonableness review can slide into the substitution of a judge's opinion for that of the prosecutor. In exercising his discretion to prove the notice, the prosecutor emphasized the key aggravating factor – the number of prior convictions. In finding that the prosecutor's decision was unreasonable, the trial judge emphasized the key mitigating factor – the 17-year gap between the prior convictions and the most recent offence. The difference between the two assessments came down to the emphasis that should be placed on the key aggravating factor as compared to the emphasis that should be placed on the key mitigating factor. This is exactly the kind of balancing that must be left to the prosecutor unless the decision is contrary to the principles of fundamental justice outlined above.
 The s. 7 jurisprudence provides a further reason for rejecting reasonableness as a principle of fundamental justice. If decisions can be reviewed for reasonableness under s. 7, the arbitrariness standard of review, a firmly entrenched principle of fundamental justice, becomes redundant. There would be little point in reviewing state action for arbitrariness if reasonableness were a principle of fundamental justice. Clearly, all arbitrary decisions would be unreasonable, but not all unreasonable decisions would be arbitrary as that word has been defined in the s. 7 jurisprudence.
 In summary, a review for reasonableness is unsupported in the case law, inconsistent with the recognized standards of review under s. 7, and incompatible with the recognized roles of the prosecutor and the trial judge. The trial judge should not have inquired into the reasonableness of the prosecutor's exercise of his discretion.