Does a defendant have to plead guilty under section 1192.1 of the Penal Code to a charge of assault?

9 As defendant himself admits, the statutory provision he actually attacks is Penal Code section 1192.4: "If the defendant's plea of guilty pursuant to Section 1192.1 or 1192.2 is not accepted by the prosecuting attorney and approved by the court, the plea shall be deemed withdrawn and the defendant may then enter such plea or pleas as would otherwise have been available. The plea so withdrawn may not be received in evidence in any criminal, civil, or special action or proceeding of any nature, including proceedings before agencies, commissions, boards, and tribunals." It is not clear to us that section 1192.4 would bar a defendant from offering in mitigation his expressed willingness to plead guilty--when that expressed willingness does in fact tend to show remorse, etc. The fundamental purpose of the statutory provision appears to be to prevent a prosecutor from presenting such evidence as an admission of guilt. (See People v. Hamilton (1963) 60 Cal.2d 105, 113-114, 32 Cal.Rptr. 4, 383 P.2d 412.)