This was particularly important with New Zealand hosting the Rugby World Cup, the third largest sporting event in the world, he said. The World Cup will be played in September and October and political commentators believe the fortunes of the New Zealand All Blacks could have a bearing on the government's re-election chances.

Key also ended speculation about a possible coalition line up, saying his centre-right National Party could continue with its current partners, the Maori Party, which campaigns for indigenous rights, and the pro-free market ACT. However, he would rather hand the reins of power to the centre-left Labour Party than work with Winston Peters, the leader of the populist New Zealand First Party, and a kingmaker in previous National and Labour-led coalitions.

"I don't see a place for a Winston Peters-led New Zealand First in a government that I lead. Historically, he has always been sacked by prime ministers," Key said. "If Winston Peters holds the balance of power it will be a Phil Goff-led Labour government," Key said. Key, who led the National Party to victory three years ago to end nine years of Labour Party rule, has already set the tone of the election in his state-of-the-nation address last week.

The prime minister said he was preparing to go to the polls with a plan to partly privatise several state-owned enterprises, including Air New Zealand, in an effort to bring down the country's mounting debt. Opposition Labour Party leader Phil Goff, in his speech, promised income tax cuts and the elimination of tax on fresh fruit and vegetables. In his election announcement, Key said the poll would also contain a referendum asked voters if they wish to keep the current proportional representation system, and if not which alternative would they prefer.

If a majority want to change, a second referendum will be held at the next election scheduled for 2014 when voters will be asked to choose between proportional representation and the most preferred alternative.