The National Rifle Association’s former ad firm has subpoenaed the gun group’s chief executive, Wayne LaPierre, for a deposition, according to a court document reviewed by The Daily Beast.

Lawyers for the NRA, who filed the document in Virginia Circuit Court on Aug. 21, are seeking to postpone LaPierre’s interview.

LaPierre isn’t the only senior NRA official who faces a grilling from ad firm Ackerman McQueen. According to the filing, the ad firm also wants to question the gun group’s top spokesperson, Andrew Arulanandam; Millie Hallow, assistant to the executive vice president; and the NRA’s chief financial officer, Craig Spray.

It’s the latest episode of an ongoing legal brawl between the powerful but troubled gun-rights group and the ad firm that helped it sally forth into America’s culture wars.

For more than three decades, there was no daylight between the two entities that was visible to outsiders. But last April, the NRA sued the firm, and within weeks, the two had parted ways. Ackerman then counter-sued the NRA, and now both entities are seeking tens of millions of dollars from the other.

The NRA’s filing says that the ad firm has refused to hand over materials responsive to its own document demands because of the NRA’s outside law firm, Brewer Attorneys and Counselors. Ackerman has argued that Brewer’s firm tried to steal its business from the NRA and has asked the judge presiding over the case to limit Brewer’s access to material it shares with the NRA.

The NRA’s filing argues that as long as Ackerman McQueen withholds materials, LaPierre and the other gun-group chiefs shouldn’t have to be deposed. LaPierre’s deposition is currently scheduled for Sep. 4, according to the filings.

It isn’t LaPierre’s only scheduled Q-and-A session. According to the New York Daily News, the New York Attorney General’s Office has also subpoenaed LaPierre as part of its investigation of the gun group.