New Zealand First leader Winston Peters says he wants to make it clear to voters where his party stands on post-election arrangements with other parties.
Mr Peters said on Sunday his party would not join a government with the National, Labour, Green or Maori parties and that New Zealand First would keep the government accountable from the Opposition benches.
Mr Peters told Morning Report that commentators have lumped his party in with Labour and others in their predictions of likely groups after the election, and he wants to set the record straight.
"We intend to go into Opposition. New Zealanders need a voice, and we're going to be that voice."
Recent opinion polls have New Zealand First on less than 3%, which is below the threshold of 5% needed to enter Parliament without an electorate seat.
Mr Peters says those polls are faulty and his party will be in Parliament.
Labour Party leader Phil Goff has not ruled out working with New Zealand First.
The leader of the National Party, John Key, says he would not consider forming a government with New Zealand First because Mr Peters is too unstable.