Prime Minister John Key has announced 26 November as the date for this year's general election and has already ruled out working with New Zealand First leader Winston Peters.
Mr Key made the announcement at an unexpected news conference at the Beehive in Wellington on Wednesday afternoon and has advised the Governor-General.
The date had been widely tipped, as it would allow a five-week election campaign to be held after the final of the 2011 Rugby World Cup on 23 October.
Mr Key said he had broken with tradition and announced the date early because he wanted to give the public certainty and allow them to plan accordingly.
He said those involved in the Rugby World Cup can focus on the tournament, the biggest event New Zealand has ever hosted, knowing the election will be held five weeks after it ends.
Mr Key says he spent some time over the summer break thinking about whether he would be prepared to work with Mr Peters or his party, but has ruled this out.
Mr Peters was embroiled in controversy before the 2008 election over donations to his party, but was cleared in several investigations.
Mr Key says it is important New Zealand has clarity about the National Party's intentions. However, he admits a vote for Mr Peters is now a vote for Labour Party leader Phil Goff as prime minister.
Mr Key says he wants to lead a positive and aspirational government and does not see a role for Mr Peters and New Zealand First in a government that he leads.
New Zealand First is not currently in Parliament, but Mr Peters says while the Prime Minister is ruling him out now circumstances often change.
"Politicians say anything and everything to try and give themselves and edge - and it most often doesn't work.
"New Zealand First prefers to wait until the people have spoken before telling the public what they're going to do. It is, after all, a democracy we live in and the election doesn't matter."
Mr Peters says New Zealand First does not rule out working with anyone but reserves the right to sit on the cross-benches, rather than supporting any other party.
He says Mr Key is obviously scared that New Zealand First will be around to prevent him selling off state-owned assets.
PM attitude arrogant - Goff
Labour Party leader Phil Goff says it is arrogant of the Prime Minister to rule out working with Winston Peters.
Mr Goff says the Prime Minister has not ruled out working with the ACT Party which has been discredited with events last year - including revelations that former MP David Garrett stole the identity of a dead baby.
Mr Goff says it is up to voters to decide who they want in government and will not make any decisions on possible coalition partners until after the election. He says he would not rule out working with Mr Peters.
He says his team of MPs and candidates are ready to begin the battle for the election and Labour will campaign on the issues affecting New Zealanders most.
The party's top priority will be to help those who are struggling to pay their bills, to create jobs and to grow the economy for the benefit of all New Zealanders, he says.