What is the test for substitute counsel in a criminal case?

"[t]he trial court is not obliged to initiate a Marsden inquiry sua sponte. [Citation.] The court's duty to conduct the inquiry arises 'only when the defendant asserts directly or by implication that his counsel's performance has been so inadequate as to deny him his constitutional right to effective counsel.' [Citations.] The defendant is not entitled to claim that an irreconcilable conflict has arisen merely because of a disagreement with counsel over reasonable tactical decisions. [Citations.]" (People v. Lara (2001) 86 Cal.App.4th 139, 150-151; accord, People v. Leonard (2000) 78 Cal.App.4th 776, 787.)

The foregoing principles "appl[y] equally preconviction and postconviction.... A defendant has no greater right to substitute counsel at the later stage than the earlier." (People v. Smith (1993) 6 Cal.4th 684, 694.)