¶1OPINION
¶2delivered the opinion of the Court,
¶3The issue we decide today is whether, absent a compelling need for the testimony, it is error to order defense counsel to testify over objection when called by the State as a fact witness. We conclude it is and reverse the judgment of the appellate court.
¶4I. The Relevant Facts
¶5A jury convicted appellant of aggravated assault, and the trial court, after finding the enhancement paragraphs true, sentenced him to fifteen years in prison. The victim was stabbed several times during a knife fight in a nightclub restroom. However, the issue of who actually stabbed him was hotly contested at trial. In support of his theory, defense counsel elicited testimony that the victim had been unable to identify the defendant during an earlier pre-trial hearing and had to ask the court interpreter who the defendant was. Although defense counsel never got a straight answer from the victim, the State requested permission to call defense counsel as a witness in an attempt to rebut this “false impression.” Defense counsel objected, but was ordered to testify as to his recollection of the incident between the victim and the interpreter. Defense counsel testified that he did not hear the victim ask the interpreter to identify the defendant.
¶6II. The Appellate Issues
¶7The exact issue upon which we granted review is “whether the court of appeals was correct in holding there is no reversible error when the State calls defense counsel as a witness to testify on behalf of the State during the guilt/innocence phase of appellant’s jury trial.” Appellant complains that (1) he was denied a “fair trial,”
¶8*147In addressing these arguments, the court of appeals concluded that appellant’s reliance on our decision in Ford v. State was misplaced; defense counsel’s credibility was not undermined by the ordered testimony; and the ineffective assistance complaint involved a “self-interest conflict,” therefore, harm was not presumed and, moreover, none was shown.
¶9III. Analysis
¶10As noted, appellant’s complaint is based on two grounds: (1) his right to a fair trial in violation of Texas and federal law, and (2) a violation of the right to effective assistance of counsel. We find appellant’s argument under the first ground compelling, and therefore do not address his second argument.
¶11It is not surprising that our decisional law is sparse when it concerns defense counsel being called to testify against his own client during the client’s criminal prosecution. In fact, over forty-five years have passed since we have addressed such a complaint. In Ford v. State
¶12Those state and federal courts that have addressed the issue of calling defense counsel as a witness in a criminal trial have been very reluctant to permit such an action.
¶13In Venable v. State,
¶14On the record before us, we conclude that the State did not demonstrate a compelling need for defense counsel’s testimony because there was no showing that the interpreter was unavailable.
¶15The court of appeals reasoned that the substance of the testimony bore only on a trivial matter and therefore could not have affected the jury’s decision. Examining the harm as resulting from just the substance of the testimony is not the proper focus. The court of appeals concluded that the “testimony neither strengthened the State’s case nor weakened Flores’s case,” and it was unlikely that, in view of the overwhelming evidence of guilt, “the average juror would have found the State’s case less persuasive had the State never called defense counsel to testify.” Flores, 90 S.W.3d at 880. This is beside the point.
¶16The facts of Venable illustrate the problem with looking to just the substance of the testimony in determining whether a defendant is harmed by this type of error. In Venable, the facts to which the attorney testified were merely collateral — i.e., whether the witness was notified by defense counsel about the criminal trial. The harm, as perceived by the Maryland court, had nothing to do with the substance of the testimony. Instead, the court addressed its concern to the overall effect of such a practice.
¶17We believe a standard harm analysis would be inadequate to address the error which is brought to bear on the proceeding itself.
¶18We hold that, when there is a compelling need to call defense attorney as a witness in the case, the trial court must take all appropriate ameliorative measures to prevent harm. Appropriate ameliorative measures include, but are not limited to: (1) substitution of another attorney to replace defense counsel once it becomes apparent that the testimony is required;
¶19A lawyer acting as witness against his client cannot properly perform his, duties to his client. With the lawyer on the stand and the client at counsel table, “it is impossible for the defendant to consult with his *151attorney.”
The adversary system of justice is predicated upon the proposition that justice will most surely prevail when adversaries are pitted one against the other. Under that system, it is the sworn duty of defense counsel to use all honorable and legal means to defend a client charged with a crime. It is inconceivable that a lawyer, seeking to convince a jury of the innocence of his client, or that the accused has not been proven guilty, can perform that high duty when he assumes the dual role of defense counsel and witness for the prosecution. Such a procedure sullies the entire legal profession. More particularly, it is manifestly unfair to the honorable trial counsel in this case, who was forced, against his will, to testify against the very client he was sworn to defend; his credibility as a lawyer immediately becomes suspect in the eyes of the jury. Above all, it was unfair to the defendant, who was convicted with the help of his own lawyer’s testimony.
¶20Thus, in accordance with our holding today, the State may indeed call defense counsel to the stand, and the court may require the lawyer testify, but the State will do so at its own peril.
¶21III. Conclusion
¶22Because the trial court did not undertake any ameliorative measures, the concerns brought about by calling defense counsel as a witness against his own client have not been assuaged here. Therefore, we reverse the court of appeals and remand for a new trial.
¶23. Appellant argued that he was denied a fair trial based on Ford v. State, 166 Tex.Crim. 347, 314 S.W.2d 101 (App.1958), Texas Disciplinary Rule of Professional Conduct 3.08 (the lawyer-witness rule), and his right to a fair trial under the Fourteenth Amendment of the United States Constitution.
¶24. Flores v. State, 90 S.W.3d 875, 880, 883 (Tex.App.-San Antonio 2002).
¶25. Appellant argues that permitting the State to call defense counsel as a witness in a criminal trial "undermines the adversarial process that is the cornerstone of the principle of Due Process guaranteed by the 14th Amendment to the United States Constitution.” We agree. One can envision the "great mischief” that may result when defense counsel is called as a prosecution witness. Hanks v. United States, 420 F.2d 412, 413 (10th Cir.1970).
¶26. 314S.W.2dat 102.
¶28. Ullmann v. State, 230 Conn. 698, 717-18, 647 A.2d 324, 334 (1994) (adopting compelling need test to be applied when either side in a criminal case seeks to call a prosecutor or defense attorney, who is or has been professionally involved in the case, to testify); see also United States v. Freeman, 519 F.2d 67, 68 (9th Cir.1975); United States v. Hall, 346 F.2d 875, 882 (2d Cir.1965) (“Defense counsel served merely as a conduit for transmission of a message.”).
¶29. See generally LaFave & Israel, Criminal Procedure § 27.6(a) (2d ed.1999) (origins of harmless error review). Texas’s former harmless error rule was promulgated in 1986. TexR.App. P. 81(b)(2).
¶30. Comment 4 to the lawyer-witness rule provides in its entirety as follows; "In all other circumstances, the principal concern over allowing a lawyer to serve as both an advocate and witness for a client is the possible confusion that those dual roles could create for the finder of fact. Normally those dual roles are unlikely to create exceptional difficulties when the lawyer's testimony is limited to the areas set out in sub-paragraphs (a)(l)-(4) of this Rule. If, however, the lawyer's testimony concerns a controversial or contested matter, combining the roles of advocate and witness can unfairly prejudice the opposing party. A witness is required to testify on the basis of personal knowledge, while an advocate is expected to explain and comment on evidence given by others. It may not be clear whether a statement by an advocate-witness should be taken as proof or as an analysis of the proof.” Tex. Disciplinary R. Prof. Conduct 3.08 (1994).
¶31. C.f. United States v. Prantil, 764 F.2d 548, 551-54 (9th Cir.1985) (discussing advocate-witness rule and concluding that, while there is no absolute bar to calling a prosecutor as a witness, sponsoring party must show "a 'compelling need’ before a participating prosecutor will be permitted to testify”); Ullmann v. State, 647 A.2d at 333-37 (adopting "compelling need” test when either party in a criminal case seeks testimony from an opposing advocate).
¶32. United States v. Schwartzbaum, 527 F.2d 249, 253 (2d Cir.1975).
¶33. C.f. Prantil, 764 F.2d at 551; United States v. Torres, 503 F.2d 1120, 1126 (2d Cir.1974) ("[t]here was no showing that any of the other people who were in the courtroom at the time Ortiz and Torres allegedly conversed, such as marshals, court clerks, court reporters or interpreters, were unavailable to testify”).
¶34. 108 Md.App. 395, 672 A.2d 123 (Md.Ct. Spec.App.1996). Venable was charged with distribution of cocaine.
¶36. Id. (citing Kaeser v. State, 96 Nev. 955, 620 P.2d 872, 874 (1980)).
¶38. As noted by the court of appeals, "[t]he interpreter's availability to testify was never explored at trial.” Flores, 90 S.W.3d at 880 n. 2.
¶39. An exception to the general rule that a party is not entitled to impeach a witness on a collateral matter exists where a witness has left a false impression concerning a matter relating to his or her credibility. Flannery v. State, 676 S.W.2d 369, 370 (Tex.Crim.App.1984). In such a case, the opposing party is allowed to correct that false impression.
¶40. It is clear to us that the situation here did not trigger the exception to the general rule preventing cross-examination on a collateral matter. See Flannery v. State, 676 S.W.2d at 370.
¶41. We find appellant’s additional argument on this point persuasive. In his brief on the merits, he states that “[t]o permit this practice breaches the integrity of the constitutional process leading to a defendant's conviction. If we are to maintain the integrity of the process, it is not enough to simply say 'the *150evidence against the defendant was overwhelming, or the testimony of the defendant’s attorney did not harm defendant, therefore, the conviction stands despite the impropriety of calling the defense attorney as a witness.' ”
¶42. State v. Livingston, 30 Ohio App.2d 232, 285 N.E.2d 75, 77 (1972) ("the fact that defendant’s counsel was called as a witness for the state taints this entire trial so that the defendant was denied the fair trial to which he is entitled.").
¶43. Strickland v. Washington, 466 U.S. 668, 686, 104 S.Ct. 2052, 80 L.Ed.2d 674 (1984).
¶44. Moreover, our examination of the record reveals that the evidence of guilt was not "overwhelming” as the court of appeals found. Flores, 90 S.W.3d at 880. For example, during the investigation, the complaining witness first identified appellant's brother as the perpetrator, who, when called to testify at appellant's trial, refused to testify, asserting his Fifth Amendment right against self-incrimination.
¶45. The trial court must inquire of the defendant — not defense counsel — whether a new attorney is desired. See Venable, 672 A.2d at 129.
¶46. Kaeser v. State, 620 P.2d at 873-74 (finding that right to appear and defend in person under Nev. Const, art 1, § 8, and an accused’s "sixth-amendment right” to counsel, offended by calling defense counsel as rebuttal witness).
¶48. See id.; Tex.R.Apf. P. 33.1.
¶49. We note that the most likely source of the information concerning the complaining witness’s inability to name his attacker was appellant, who was seated next to his'attorney.
¶50. Attempts to cross-examine oneself may take on a ludicrous appearance. State v. Thomas, 53 Or.App. 375, 631 P.2d 1387, 1390 (1981).
¶51. Id.(whether an attorney is able to retain a truly adversary posture, when it may appear to a jury that he is playing on both teams, is at least problematical.).
¶52. Bray v. State, 478 S.W.2d 89, 90 (Tex.Crim.App.1972); Summers v. State, 147 Tex.Crim. 519, 182 S.W.2d 720, 721-22 (1944).