It is rare to depose opposing counsel.  Here is an interesting case in which the question to be determined is whether plaintiff knew his union would not participate in a discrimination case, and if so, whether the statute of limitations had passed.

From Wilmer Cutler Pickering Hale and Dorr LLP :

"The Southern District of California ordered the deposition of Plaintiff’s attorney after finding that he had information crucial to Defendant’s statute of limitations defense, and that the information could not be otherwise obtained. Pastrana v. Local 9509 Commc’ns Workers of Am., No. 06cv1779 W (AJB), 2007 U.S. Dist. LEXIS 73219 (S.D. Cal. Sept. 28, 2007).

Plaintiff brought suit against Local 9509 after he was fired from his job with AT&T, and the union declined to appeal his grievance to arbitration. Id. at *3. Local 9509 raised the six-month statute of limitations as a defense to Plaintiff’s claim that it had breached its duty of fair representation. Thus the date by which the union notified Plaintiff and his attorney that it would not appeal was significant. Id. at *3-4.

If Plaintiff had been given notice by the union prior to February 28, 2006, his claim, brought on September 1, would be untimely. Id. at *4. Defendant claimed that a union employee had informed Plaintiff and his attorney via several teleconferences in February 2006 that it would not pursue his grievance to arbitration; Plaintiff disputed this account and offered a Declaration of his counsel that these teleconferences had not occurred until March 2006. Id. at *4. Defendant filed a motion to compel the deposition of Plaintiff’s counsel on the grounds that he was the only person besides Plaintiff and a union employee to participate in those conversations. Id. at *4-5. Defendant also moved to compel the production of any notes Plaintiff’s attorney took during those conversations. Plaintiff opposed the motion and moved for a protective order on the grounds that the testimony and documents sought were protected by the attorney-client privilege and work product doctrine. Id."