On August 19, 1975, the defendant, Phillip David Barnett, was indicted by the grand jury serving the Circuit Court of Nicholas County on a charge of possession of “a controlled substance, to wit: marijuana, less than 15 grams”. Upon arraignment he entered a plea of not guilty and the matter was set for trial. Subsequently, on January 9, 1976, the defendant moved the court for permission to withdraw his plea of not guilty and to enter a plea of guilty to the crime charged in the indictment. This offer to plead guilty was conditioned on its being “treated under Section 407 of the Uniform Controlled Substance Act.”
After counsel for the defendant made the offer alluded to above, the following colloquy took place:
THE COURT: Mr. Barnett, do you understand what your attorney says that you propose to do, that you propose to withdraw your plea of not guilty heretofore entered and to enter a plea of *8guilty to the charge contained in this indictment of unlawfully and knowingly possessing marijuana less than fifteen grams?
THE DEFENDANT: Yes, sir.
THE COURT: Is that what you want to do?
THE DEFENDANT: Yes, sir.
THE COURT: All right, then the Court will accept your plea of guilty, and is it a fact that he did two years ago enter a plea similar to this and was placed on probation?
MR. GARRETT: I don’t have any reason to dispute that, your Honor.”
On March 31, 1976 the court, refusing to place defendant on probation under the provisions of W.Va. Code, 1931, 60A-4-407, as amended, sentenced him to a term of six months in the Nicholas County jail and fined him $500.00. In the following language the court related its reason for sentencing the defendant to jail instead of granting probation: “under section 407 it says there may be only one discharge and dismissal under this section with respect to any person.” Reasoning that the defendant had previously been discharged under this section, the court refused to again apply the probation provisions thereof and imposed the sentence under W.Va. Code, 1931, 60A-4-401, as amended. This appeal followed.
It is the position of the defendant on this appeal that the trial court erred, (1) by treating the defendant as a second offender; (2) by accepting a plea of guilty upon condition that it be treated under Section 407 and then refusing to proceed under said section; and, (3) by accepting the defendant’s plea of guilty without first determining whether it was made voluntarily.
In determining whether the trial court erred in treating the defendant as a second offender it is necessary to consider the pertinent provisions of W.Va. Code, 1931, 60A-4-401 and 407 as amended. Section 401, after describing the prohibited act and prescribing the penalties, concludes:
*9Provided, that notwithstanding any other provision of this chapter to the contrary, any first offense for possession of less than 15 grams of marihuana shall be disposed of under said section 407.
Section 407, in pertinent part, provides.
Whenever, any person who has not previously been convicted of any offense under this chapter ... relating to narcotic drugs, marihuana ... pleads guilty to or is found guilty of possession of a controlled substance under section 401 (c) [§ 60A-4-401 (c)], the court, without entering a judgment of guilt and with the consent of the accused, may defer further proceedings and place him on probation upon terms and conditions. ... Upon fulfillment of the terms and conditions, the court shall discharge the person and dismiss the proceedings against him. Discharge and dismissal under this section shall be without adjudication of guilt and is not a conviction for purposes of this section ... The effect of such dismissal and discharge shall be to restore such person in contemplation of law to the status he occupied prior to such arrest and trial. No person as to whom such dismissal and discharge have been effected shall be thereafter held to be guilty of perjury, false swearing, ... by reason óf his failure to disclose or acknowledge such arrest or trial in response to any inquiry made of him for any purpose. There may be only one discharge and dismissal under this section with respect to any person ....”
Section 401 clearly provides that any first offense shall be disposed of under Section 407. It is clear from the record that this is not the defendant’s first offense of possession of less than 15 grams of marihuana. While he was under no obligation under Section 407 to admit a first offense, he and his counsel readily admitted to the court that he had experienced a former offense and had been placed on probation therefor. Furthermore, the same judge who presided in the instant case placed him on probation for such former offense.
*10Section 401 refers to “any first offense,” not to a conviction. The defendant having fulfilled the terms of his probation, under the provisions of Section 407, suffered no former conviction. However, in the circumstances described above, this was not a first offense and the court was under no mandate to apply the provisions of Section 407.
The second assignment of error, the acceptance of a guilty plea under condition that it be treated under Section 407, is meritorious and compels us to reverse. The record clearly reveals, as noted above, that the plea of guilty was entered upon the condition that the defendant would be treated under Seciton 407. A full consideration of the record further reveals that when the defendant agreed to enter a guilty plea, he was led to believe that he would receive probation under such section of the code.
A guilty plea is a most serious waiver of a constitutional right — the right to a trial by jury, the privilege against compulsory self-incrimination and the right to confront accusers. It has been described as the most devastating waiver possible under our constitution. See, United States v. Truglio, 493 F.2d 574 (4th Cir. 1974). See also, 5B M.J. Criminal Procedure, Section 33 and cases cited in the footnotes thereto.
It is the general rule that, in the absence of statutory authority, a court cannot accept a plea of guilty offered on any kind of condition. A guilty plea must manifest an unequivocal and knowledgeable admission of the offense charged and should not be accepted if conditional. See, State v. Watson, 1 Wash. App. 43, 459 P.2d 67 (1969); Wayne v. State, 4 Md. App. 424, 243 A.2d 19 (1968);United States v. Brierley 404 F.2d 790 (3rd Cir. 1968); Hulsey v. United States, 369 F.2d 284 (5th Cir. 1966); Roberts v. Warden, Maryland Penitentiary, 221 Md. 576, 155 A.2d 891 (1959).
In the instant case the defendant’s colloquy with the court precluded his guilty plea from being clear, definite and unconditional. In such circumstances the guilty plea *11was unacceptable and the court should not have acted upon it. Furthermore, it is clear from the record that the court erred in failing to first determine the volun-tariness of the plea as set out in Call v. McKenzie,_ W. Va. _, 220 S.E. 2d 665 (1975).
For the reasons stated herein, the judgment of the Circuit Court of Nicholas County is reversed and the case is remanded for a new trial.
Reversed and remanded for a new trial.