Helen Clark has said she will stand down as Labour Party leader after conceding defeat to John Key.
She said she is proud of what she has achieved in nine years as Prime Minister and it is time to go after losing the election.
With less than one per cent of the vote left to count National has 45.5 per cent of the vote to Labour's 33.8 per cent.
National has 59 seats and will make that up to a coalition of 65 MPs with Act's 5 seats and Peter Dunne from United Future.
Clark said at Labour Party HQ tonight: "Tonight is a night for the winners to savour but we won't be going away."
She warned against what Labour had achieved "going up in the flames of right wing of politics" before revealing she would stand down.
"My job as Labour leader is done."
She said the new leader, who she expected would be appointed before Christmas, would have her full loyalty and support.
Helen Clark made the announcement after telling the Labour party faithful that she accepted the responsibility for the Labour loss.
She congratulated John Key on his victory.
"So with that, it's over and out from me. Thank you once again and thank you New Zealand for the privilege of being prime minister for the last nine years."
Rodney Hide told his Act supporters at Orakei RSA that Key had just rung to congratulate him. Hide said Key told him they would meet on Monday to discuss the formation of a new government.
Former National prime minister Jenny Shipley described the results as a thrashing.
"I think John Key is going to make a fine prime minister. I'm thrilled," she said.
Several high profile Labour MPs have lost their seats. Judith Tizard has been tipped out of the Auckland Central seat she has held since 1996 by National's Nikki Kaye, a 28-year-old businesswoman and relative newcomer to politics.
The historic West-Coast-Tasman has fallen to National's Chris Auchinvole with Damien O'Connor the casualty.
Harry Duynhoven has lost his New Plymouth seat in a substantial swing to National and Jonathan Young.
Mr Duynhoven, the Minister for Transport Safety and Associate Minister of Energy, is not on the Labour list, so will be out of Parliament.
Labour has also lost the most marginal seat in New Zealand. Otaki, held by Labour by just 382 votes, has fallen to National's Nathan Guy who claimed the seat over Darren Hughes. Up and comer Hughes, though, may get back into Parliament on his high list position for Labour.
Meanwhile, Winston Peters, one of New Zealand's most flamboyant politicians, has lost his place in Parliament, for the first time in more than 30 years.
Conceding defeat, he congratulated National's Simon Bridges and said it was all about democracy.
However, he told supporters and reporters that "this is not the end.".
Progressive Leader Jim Anderton has congratulated Key on his victory and wished him well, but he is promising to keep a close eye on the incoming right wing government from opposition.
"I'm going to enjoy the next three years in a way. I'm a good guerilla fighter and there's a lot to fight for I can tell you."
Act had a strong showing with 3.7 per cent of the vote.