An airline that missed out on landing rights at Milford Sound is calling into question the Department of Conservation's tender process.
Aspiring Air chief executive David Horsburgh says the 40-year-old airline will be forced to close because of the decision.
Thirty-six companies applied for 23 landing concessions under the department's revised air plan for Milford, which is designed to reduce noise in the national park.
Mr Horsburgh says he was told by the department to reapply just for the landing rights used in the past by Aspiring Air.
But he says other companies were told to compete for his landing rights, which means he should have gone after their rights too.
He says he is taking his grievance to the Government.
The department says a competitive tender process will always leave some parties unhappy.