Carole Pappa and her codefendant, Doctor Raymond Bernard Pinch, were each charged with murder and conspiracy to commit murder. The action was originally set for trial before Judge James G. Whyte, but he was disqualified upon a challenge by the People pursuant to the provisions of section 170.6 of the Code of Civil Procedure.1 *353Judge Clement D. Nye, who was then assigned to hear the case, was disqualified upon a challenge by Pinch under the samo section, and the action was finally tried before Judge Walter R. Evans. The jury was unable to agree, and a mistrial was declared.
The action was set for retrial and is now pending before Judge LeRoy Dawson. Thirteen days prior to the date fixed for commencement of the retrial Mrs. Pappa, who had not previously attempted to exercise any rights under section 170.6, moved to disqualify Judge Dawson pursuant to the provisions of that section. The motion was denied, Mrs. Pappa commenced this proceeding to prevent Judge Dawson from hearing her case, and we granted an alternative writ of prohibition.
Section 170.6 provides that no judge shall try any action or special proceeding when it is established by an affidavit that he is prejudiced against a party or attorney so that the party or attorney cannot, or believes he cannot, have a fair and impartial trial before such judge. Facts showing prejudice need not be alleged or proved, and, where a timely motion to disqualify is made, supported by an affidavit alleging prejudice, the case or matter, without any further act or proof, must be assigned to another judge for trial or hearing.
Subdivision (3) of section 170.6 provides in part: “Under no circumstances shall a party or attorney be permitted to make more than one such motion in any one action . . . ; and in actions . . . where there may be more than one plaintiff or similar party or more than one defendant or similar party appearing in the action . . . only one motion for each side may be made in any one action.” (Italics added.) A criminal action is defined as the “proceeding by which a party charged with a public offense is accused and brought to trial and punishment. ...” (Pen. Code, § 683; see also Code Civ. Proc., § 22.) It is clear that Pinch’s motion to disqualify Judge Nye must be considered as having been made in the pending “action” and that the retrial will not be a new “action” within the meaning of the italicized language of subdivision (3).
The question is whether the codefendants constitute a “side” as that term is used in subdivision (3). If so, Mrs. Pappa will not be entitled to have Judge Dawson disqualified since Pinch had previously exercised a challenge under section 170.6. In Johnson v. Superior Court, 50 Cal.2d 693 [329 P.2d 5], we recognized that although there are ordi*354narily two “sides” to a case, there may he more if codefendants have substantially adverse interests. The reasoning in Johnson, a civil case, is equally applicable to a criminal prosecution.
The burden is upon Mrs. Pappa to establish that her interests are substantially adverse to those of her co-defendant, Pinch. She, of course, is in a better position than the prosecution to acquaint the court with the basis of her claim, and the obligation to do so does not subject her to undue hardship. In this connection it must be remembered that until the enactment of section 170.6 in 1957 a party seeking to disqualify a judge on the ground of bias had to allege and prove the facts relied upon to establish prejudice. That procedure, which is contained in section 170 of tlie Code of Civil Procedure, remains available in a criminal as well as a civil action. Section 170.6, as we have seen, relieves a party of the necessity of specifying the facts relied upon as the basis of disqualification upon the ground of bias, and it thus extends a special privilege subject to the conditions set forth in the section. As pointed out in Johnson v. Superior Court, these conditions were imposed as safeguards designed to minimize abuses of the privilege. (50 Cal.2d 693, 697.) If for some reason a party does not desire to assume the burden of establishing that he comes within these conditions, he may pursue the alternative procedure under section 170 of alleging and proving the facts upon which he relies to establish prejudice.
The showing made by Mrs. Pappa is very meager. She asserts that a conflict of interest between herself and Pinch exists because the record of the first trial will show that it has always been the theory of the People that Pinch was the principal and that her role was that of an aider and abettor. She states that in view of the widespread interest in her ease the court must have some knowledge of it and that the transcript of the first trial will show that her position is substantially adverse to that of Pinch. It also appears that she made a motion for a separate trial, which was denied, and that she opposed a motion for change of venue made by Pinch.
It is not claimed that this is a case where each defendant is attempting to avoid conviction by shifting responsibility for the homicide to the other, but, to the contrary, under Mrs. Pappa’s assertions with respect to the theories of the prosecution, it appears likely that Pinch’s defenses against the charge that he was the principal would support *355her defense against the charge of aiding and abetting. Although differences of opinion between codefendants as to procedural matters such as the desirability of a change of venue or a separate trial might, under some circumstances, show the existence of substantially adverse interests, it should not be assumed that this is true in the absence of a showing of what the circumstances are and how they affect each of the parties and the relationship between them. Mrs. Pappa does not give her reasons for seeking a separate trial or for opposing Pinch’s motion for change of venue, and it does not appear that these matters were sufficiently important to amount to a substantially adverse interest. Moreover, the prosecution asserts, and it is not disputed, that no evidence was introduced before Judge Dawson to establish that a conflict of interest existed between the two defendants. A showing on this matter should have been made by the moving party in the trial court before relief was sought here.
It does not follow from the fact that Mrs. Pappa and Pinch are represented by separate counsel that their interests are adverse. The cases of People v. Robinson, 42 Cal.2d 741, 745 et seq. [269 P.2d 6], and People v. Lanigan, 22 Cal.2d 569, 576-577 [140 P.2d 24, 148 A.L.R. 176], which involved court-appointed attorneys and the constitutional right to counsel, are not analogous to the situation here. In each of those cases the trial court, over objection, forced upon a defendant an attorney who represented a eodefendant, and we held that every defendant is entitled to the undivided loyalty and untrammeled assistance of counsel of his own choice entirely apart from any diversity of interests. A different situation is presented where, as here, a limited privilege is involved which would not be available in the absence of a special statute and cannot be exercised except in accordance with that statute. The privilege conferred by section 170.6, unlike the right to counsel, may be exercised by more than one eodefendant only where they have substantially adverse interests, and obviously the mere fact that they choose to be represented by separate counsel does not show that such a conflict of interests exists. Nor does the fact that an attorney may exercise the privilege under section 170.6 mean that the limitation of one motion to each “side” may be ignored and that the attorney may challenge a judge irrespective of whether disqualification of another judge has previously been obtained by his client or by a codefendant whose interests are not adverse to those of the client. Other*356wise, a party who exercised a challenge could continue to obtain disqualifications endlessly by the simple expedient of changing attorneys.
Under all the circumstances it seems clear that Mrs. Pappa has not established that she has interests substantially adverse to those of Pinch.
Particular emphasis is placed by Mrs. Pappa on the fact that Pinch and the prosecution have each been permitted to disqualify a judge, and she contends that the constitutional guarantees of fairness and equality require that she also be permitted to do so. A similar argument was made in Johnson v. Superior Court, 50 Cal.2d 693, 700 [329 P.2d 5], where it was said as to the provision limiting each “side” to one challenge: “The Legislature could reasonably determine that this limited restriction was justified in order to prevent the undue delays which could otherwise occur, and we hold that section 170.6 does not arbitrarily discriminate against multiple parties.”
The alternative writ is discharged, and a peremptory writ is denied. This order is final forthwith.
Traynor, J., McComb, J., White, J., and Dooling, J., concurred.
Appendix
Section 170.6 of the Code of Civil Procedure reads as follows:
‘‘(l) No judge of any superior, municipal or justice court of the State of California shall try any civil or criminal action or special proceeding of any kind or character nor hear any matter therein which involves a contested issue of law or fact when it shall be established as hereinafter provided that such judge is prejudiced against any party or attorney or the interest of any party or attorney appearing in such action or proceeding.
‘ ‘ (2) Any party to or any attorney appearing in any such action or proceeding may establish such prejudice by an oral or written motion without notice supported by affidavit that the judge before whom such action or proceeding is pending or to whom it is assigned is prejudiced against any such party or attorney or the interest of such party or attorney so that such party or attorney cannot or believes that he cannot have a fair and impartial trial or hearing before such judge. Where the judge assigned to or who is scheduled to try the cause or hear the matter is known at least 10 days before the date set for trial or hearing, the motion shall be made at least five days before that date. If directed to the trial of a cause where there is a master calendar, the motion shall be made to the judge supervising the master calendar not later than the time the cause is assigned for trial. In no event shall any judge entertain such motion if it be made after the drawing of the name of the first juror, or if there be no jury, after the making of an opening statement by counsel for plaintiff, or if there be no such statement, then after swearing in the first witness or the giving of any evidence or after trial of the cause has otherwise commenced. If the motion is directed to a *357hearing (other than the trial of a cause), the motion must be made not later than the commencement of the hearing. In the case of trials or hearings not herein specifically provided for, the procedure herein specified shall be followed as nearly as may be.
11 (3) If such motion is duly presented and such affidavit is duly filed, thereupon and without any further act or proof, the judge supervising the master calendar, if any, shall assign some other judge to try the cause or hear the matter. In other eases, the trial of the cause or the hearing of the matter shall be assigned or transferred to another judge of the court in which the trial or matter is pending or, if there is no other judge of the court in which the trial or matter is pending, the chairman of the judicial council shall assign some other judge to try such cause or hear such matter as promptly as possible. Under no circumstances shall a party or attorney be permitted to make more than one such motion in any one action or special proceeding pursuant to this section; and in actions or special proceedings where there may be more than one plaintiff or similar party or more than one defendant or similar party appearing in the action or special proceeding, only one motion for each side may be made in any one action or special proceeding.
‘1 (4) Unless required for the convenience of the court or unless good cause is shown, a continuance of the trial or hearing shall not be granted by reason of the making of a motion under this section. If a continuance is granted, the cause or matter shall be continued from day to day or for other limited periods upon the trial or other calendar and shall be reassigned or transferred for trial or hearing as promptly as possible.
“ (5) Any affidavit filed pursuant to this section shall be in substantially the following form:
(Here set forth court and cause)
State of California )
County of ) s '
...................................., being first duly sworn, deposes
and says: That he is a party (or attorney for a party) to the within
action (or special proceeding). That ..............................
the judge before whom the trial of the (or a hearing in the) aforesaid action (or special proceeding) is pending (or to whom it is assigned), is prejudiced against the party (or his attorney) or the interest of the party (or his attorney) so that affiant cannot or believes that he cannot have a fair and impartial trial or hearing before such judge.
Subscribed and sworn to before me
this.....day of ..............,19 ....
(Clerk or Notary Public or other officer administering oath)
“(6) Nothing in this section shall affect or limit the provisions of Section 170 and Title 4, Part 2, of this code and this section shall be construed as cumulative thereto.
“ (7) If any provision of this section or the application to any person or circumstance is held invalid, such invalidity shall not affect other provisions or applications of the section which can be given effect without the invalid provision or application and to this end the provisions of this section are declared to be severable. ’ ’
Section 170.6 of the Code of Civil Procedure is set forth in an appendix to this opinion [post, p. 349],