NY2d 1067 [1993]; Imperiale v Prezioso, supra at 720; see also CPLR 105 [u]). To establish a prima facie case of legal malpractice, a plaintiff is required to establish the existence of an attorney-client relationship at the time of the alleged malpractice, that the attorney was negligent, that the negligence was a proximate cause of the loss sustained and that the plaintiff suffered actual, ascertainable damages (see Brodeur v Hayes, 18 AD3d 979, 980 [2005], lv dismissed and denied 5 NY3d 871 [2005]; Maddux v Schur, 16 AD3d 873, 874 [2005]; see also Davis v Klein, 88 NY2d 1008, 1009-1010 [1996]). To establish proximate cause, plaintiffs must “show that [they] would have been successful in the underlying action” (Brodeur v Hayes, supra at 980; see Servidone Constr. Corp. v Security Ins. Co. of Hartford, 64 NY2d 419, 425 [1985]; Pollicino v Roemer & Featherstonhaugh, 277 AD2d 666, 668 [2000]).
Plaintiffs allege that defendants negligently represented them in their underlying trespass and nuisance suit against the Town of Marlborough, which was resolved in favor of the Town following a nonjury trial (Amodeo v Town of Marlborough, 307 AD2d 507 [2003]). Plaintiffs claim that defendants failed to disclose a conflict of interest until the middle of trial, necessitating hurried retention of substitute counsel and, during this period, neglected to adequately prepare plaintiffs’ case or request additional witnesses, causing the trial court to preclude some of their expert and fact witnesses (id. at 509). Under settled law, not every conflict of interest or violation of disciplinary rules amounts to actionable negligence by an attorney, although “liability can follow where the client[s] can show that [they] suffered actual damage as a result of the conflict” (Tabner v Drake, 9 AD3d 606, 610 [2004]).
Plaintiffs’ submissions, at most, could establish defendants’ negligence and conflict of interest but not that plaintiffs “would have been successful” (Brodeur v Hayes, supra at 980) “but for” those failings (Davis v Klein, supra at 1009-1010). As such, plaintiffs did not establish a meritorious cause of action and, thus, defendants’ motion to dismiss should have been granted (see Hommell v Albany Med. Ctr. Hosp., supra at 772).
Cardona, P.J., Mercure and Crew III, JJ., concur. Ordered that the order is reversed, on the law, with costs, motion granted and complaint dismissed.