International tourists could be charged to enter national parks under plans presented to Tourism Minister John Key.
The briefing warns Mr Key, who is also Prime Minister, that Government policy, coupled with increasing demand from international tourists, could lead to "negative outcomes for New Zealanders".
It says these include congestion in national parks, increasing lower-value visitors, environmental degradation and inefficient infrastructure investment.
The briefing from the Ministry of Economic Development said access to major Government-owned tourism assets was "often free or heavily subsidised".
"So increasing demand from non-residents in such cases may not translate into value for New Zealand."