Leaked documents show National Party board members have raised concerns about party supporter Simon Lusk.
Earlier this year, the Labour Party tried to link Mr Lusk to the controversy over leaks at the Accident Compensation Corporation (ACC).
During a board meeting in March, National's whip Michael Woodhouse raised concerns about an alternative school Mr Lusk is running for potential National Party candidates, which is unsanctioned by the party.
Mr Lusk has held official party roles in the past, including on local electorate campaigns.
The board was told Mr Lusk has a negative agenda, which poses a serious risk to National.
Prime Minister John Key has a place on the board, but was absent from the meeting in March.
Mr Key says he is unaware of any criticism of Mr Lusk at board level, although he says people hold a range of views.
"I'm sure there are one or two people who might have concerns, but I don't have any great concerns."