—Appeal from that part of an order of Supreme Court, Monroe County (Lunn, J.), entered October 17, 2001, that denied plaintiffs motion to disqualify the law firm of Biernbaum, Inclima & Meyer, LLP, from representing defendant.
It is hereby ordered that the order insofar as appealed from be and the same hereby is reversed on the law without costs and the motion is granted.
Memorandum: Supreme Court erred in denying plaintiffs motion to disqualify the law firm representing defendant in this matrimonial action. Plaintiff met his burden of demonstrating that at least one member of the law firm representing defendant ought to be called as a witness on behalf of defendant with respect to her counterclaim seeking to set aside an equitable distribution agreement (agreement) that was executed in 1992 (see Code of Professional Responsibility DR 5-102 [c] [22 NYCRR 1200.21 (c)]; Clifford v Montana Mills Bread Co. [appeal No. 1], 275 AD2d 909; Chang v Chang, 190 AD2d 311, 318-319). In her counterclaim, defendant alleges that the agreement was the product of fraud, that she entered into the agreement under duress, and that the agreement is unconscionable. In support of his motion, plaintiff submitted evidence in the form of a letter from defendant’s present attorney to defendant stating that, consistent with the advice he had given her during a conference eight days earlier, he was advising her that the agreement would be detrimental to her and strongly recommended that she not sign it. In addition, the attorney alluded to defendant’s mental state at that time. Because defendant’s attorney was “an active participant in a disputed transaction and has personal knowledge of the underlying circumstances, he ought to be called as a witness on behalf of his client and it is improper for him to continue his representation” (Chang, 190 AD2d at 318; see also Johnson, Mullan & Brundage v Folkman, 294 AD2d 857). Any doubt *892concerning the necessity for the attorney’s testimony should be resolved in favor of disqualification (see Matter of Stober v Gaba & Stober, 259 AD2d 554, 555; 108th St. Owners Corp. v Overseas Commodities, 238 AD2d 324, 326).
All concur except Hayes and Scudder, JJ., who dissent and vote to affirm in the following memorandum.