What is the legal test for a motion to disqualify an attorney?

discretion is limited by the applicable legal principles. [Citation.] Thus, where there are no material disputed factual issues, the appellate court reviews the trial court's determination as a question of law. [Citation.]" (People ex rel. Dept. of Corporations v. SpeeDee Oil Change Systems, Inc. (1999) 20 Cal.4th 1135, 1143-1144.)

"A trial court's authority to disqualify an attorney derives from the power inherent in every court '[t]o control in furtherance of justice, the conduct of its ministerial officers, and of all other persons in any manner connected with a judicial proceeding before it, in every matter pertaining thereto.' [Citations.]" (People ex rel. Dept. of Corporations v. SpeeDee Oil Change Systems, Inc., supra, 20 Cal.4th at p. 1145.)

"A disqualification motion involves a conflict between a client's right to counsel of his or her choice, on the one hand, and the need to maintain ethical standards of professional responsibility, on the other. [Citation.] Although disqualification necessarily impinges on a litigant's right to counsel of his or her choice, the decision on a disqualification motion 'involves more than just the interests of the parties.' [Citation.] When ruling on a disqualification motion, '[t]he paramount concern must be to preserve public trust in the scrupulous administration of justice and the integrity of the bar. The important right to counsel of one's choice must yield to ethical considerations that affect the fundamental principles of our judicial process.' [Citations.]" (Clark v. Superior Court (2011) 196 Cal.App.4th 37, 47-48.)

2. Standing