A power struggle at the NRA has pitted Wayne LaPierre, the gun-rights group’s executive vice president, against its newly installed president, Oliver North.

In a letter to board members on Thursday, which was published by The Wall Street Journal, LaPierre accused North of an extortion plot in an effort to oust him.

“Leaders in every walk of life must often choose: between what is true, and what is polite; between what is convenient, and what is right,” LaPierre wrote in the letter.

“Yesterday evening, I was forced to confront one of those defining choices—styled, in parlance of extortionists, as an offer I couldn’t refuse,” he added.

LaPierre went on to claim that North, who rose to prominence in the 1980s for his role in the Iran-Contra scandal, called a senior staff member and threatened to distribute a damaging letter to board members that detailed sexual harassment claims and excessive wardrobe and travel expenses. It was not clear who was being accused of these misdeeds.

In a statement to The Journal, a lawyer for the NRA, said: “many of the issues raised by Col. North have been the subject of review and investigation by the NRA since early last year. In our view, the items involving Mr. LaPierre may reflect a misinformed view of his and the NRA’s commitment to good governance.”

North then said, according to the letter, that if LaPierre resigned as executive vice president, he would not send the letter to the board.

At the heart of the conflict between the two execs is a legal battle between the NRA and one of their contractors, media company Ackerman McQueen.

The NRA sued Ackerman McQueen, which operates online video service NRATV, earlier this month, claiming they hid information about how they spend the tens of millions of dollars the NRA gives them annually.

Ackerman McQueen employs North, who hosts a documentary series on NRATV.

LaPierre claims in the letter that the media company pays North millions of dollars annually for his work on the series, but the company has only produced three episodes in the last year.

Earlier this year, the NRA sent a letter to the company demanding to know what they were paying for, according to LaPierre’s letter.

“AM did not respond directly,” LaPierre wrote. “But appears to have responded indirectly by trying to oust me.”

The NRA did not return a request for comment.