Does substitute counsel need to be appointed in future?

In People v. Marsden, supra, 2 Cal.3d 118, 123, 84 Cal.Rptr. 156, 465 P.2d 44, we held that substitute counsel must be appointed if in future proceedings " 'the right to the assistance of counsel would be substantially impaired ... in case the request is not granted....' " (Italics added.) The majority agrees that this continues to be the test upon which the court's discretion to appoint substitute counsel is to be exercised. "Denial of the motion is not an abuse of discretion unless the defendant has shown that a failure to replace the appointed attorney would 'substantially impair' the defendant's right to assistance of counsel." (People v. Webster (1991) 54 Cal.3d 411, 435, 285 Cal.Rptr. 31, 814 P.2d 1273.)