What is the defense attorney's duty to oppose the prosecution at trial?

The error in this case--the trial court's discharge of the jury before the prosecution presented evidence of defendant's prior convictions--was committed by the trial court and was abetted by the neglect of the prosecution when it failed to bring the error to the trial court's attention. In a criminal trial, the defense attorney's obligation is to diligently and conscientiously act as an advocate for the defendant (see, e.g., In re Cordero (1988) 46 Cal.3d 161, 180, 249 Cal.Rptr. 342, 756 P.2d 1370), not to perform any obligations incumbent on the trial court or to ameliorate the prosecution's deficiencies at trial. It is the task of the prosecution to allege the prior conviction in the accusatory pleading (Pen.Code, 969) and to prove its truth beyond a reasonable doubt (People v. Morton, supra, 41 Cal.2d at p. 539, 261 P.2d 523). Thus, in this case, any duty to object should be imposed on the prosecution, not the defense. To hold, as the majority does, that defense counsel must interpose an objection that could result in substantial detriment to the client, and that could not advance the client's interests, is inconsistent with counsel's responsibilities, is anathema to our adversarial system, and is contrary to the allocation of the duties and obligations of the participants in our judicial system.