The nation’s leading gun-control advocacy group filed a complaint Friday with the Senate Ethics Committee charging Sen. Larry Craig (R-Idaho) with “serving two masters,” referring to his legislative role on gun issues and his board position with the National Rifle Association.

Craig, the author and floor manager of a bill to immunize gun manufacturers and some trade groups from lawsuits, has been a longtime member of the NRA board of directors.

“Senator Craig has impermissibly acted in his capacity as a Senator to further the interests, including the financial interests, of an organization for which he serves as a member of the board of directors,” the Brady Campaign To Prevent Gun Violence wrote in its letter to the Ethics Committee.

But Craig’s office dismissed the accusation. His bill would not provide legal immunity to the NRA, which was meant to qualify as a civil rights group under his legislation; only a trade group such as the National Shooting Sports Foundation would be exempted from lawsuits, aides said.

“This bill does not cover the NRA. The immunity granted in this bill would not cover the NRA,” said Dan Whiting, Craig’s press secretary. “It was never our intention.”

Whiting said that if the bill is not written clearly enough, Craig’s staff would do “whatever we need to do to clarify it.”

The complaint comes in the middle of the gun lobby’s biggest legislative fight in a decade: the attempt to end any current or future lawsuits against gun manufacturers and, as the GOP’s talking points put it, “related trade associations.” Dozens of lawsuits have been filed against gun manufacturers around the nation by cities and interest groups.

Craig has often been the lead promoter of gun-rights legislation in the Senate, leading the fight to end the assault-weapons ban and trying to prevent manufacturers from being forced to implement child-safety locks.

But Brady campaign officials contend the gun immunity legislation does protect the NRA, and that this issue isn’t at all about the Second Amendment, rather a pure financial benefit to a specific industry and its trade groups.

“This isn’t a matter of gun rights, this is a matter of money and the financial interests of this industry,” said Michael Barnes, president of the Brady Campaign.