The National Rifle Association's top lobbyist resigned Wednesday, the latest development in a dizzying array of in-fighting within the gun lobbying group in recent months that has ensnared even its most ardent loyalists.

Chris Cox's departure came the same day the NRA confirmed it was severing ties with its longtime public relations firm and suspending operation of NRATV, an online station that has stirred controversy for its fiery rhetoric.

Cox, long viewed as the likely successor to longtime CEO Wayne LaPierre, resigned just about a week after the NRA put him on administrative leave, claiming he was part of a failed attempt to extort LaPierre and push him out. It came within hours of NRA officially severing ties with Ackerman McQueen, the Oklahoma-based public relations firm with which it's been embroiled in a legal tangle over expenditures.

Cox had been the executive director of NRA's lobbying arm, the Institute for Legislative Action, since 2002. He was credited with leading efforts to allow a decadelong ban on "assault weapons" to expire in 2004, an achievement that allowed the gun industry to resume selling what the industry calls "modern sporting rifles" and critics claim are used too often to exact mass carnage.

His resignation was confirmed by NRA spokesman Andrew Arulanandam. No other comment was immediately made about his departure. A spokesperson for the NRA's lobbying arm did not immediately return a message seeking comment.

However, when he was suspended, Cox said in a statement obtained by The New York Times that allegations he had been part of a group seeking LaPierre's ouster were "offensive and patently false. For 24 years I have been a loyal and effective leader in this organization."

Cox played his usual prominent role at the NRA's annual meetings and there was little public evidence that he and LaPierre or the NRA's board of directors were at odds. But the in-fighting spilled out during what is normally a pep rally of sorts among gun-rights enthusiasts when Oliver North , then the NRA president, threatened to expose questionable personal and travel expenses unless LaPierre stepped down. Instead, LaPierre turned the tables on North and accused him of trying to extort him into submission.

In the months since, NRA has taken repeated legal action against Ackerman McQueen, accusing it of refusing to document its billings and being in cahoots with North. NRA has paid Ackerman McQueen tens of millions of dollars in the decades since they partnered up to shape NRA's messaging.

A prominent part of NRA's public relations is NRATV which features hosts who talk about everything from immigration to gun rights. In a statement from LaPierre posted on the NRA website, the gun lobbying group said it would no longer be airing live programming on NRATV and would be evaluating the station's future.