Labour has gone for the heartstrings in TV ads to be aired today while National has taken a more light-hearted approach as the on-screen political campaign begins.
Under electoral rules, parties can begin using their allocated broadcasting airtime this morning.
In its first television ad, the National Party aims to help voters make a "simple choice" between its own management of the economy or a Labour-Greens-Internet-Mana leadership.
National portrays itself as a young, hard-working, sleek rowing team "staying on course".
It is competing against a hapless, bumbling rowing boat with two red and green cockswains, and one of its rowers in Internet-Mana purple.
In a voiceover, the ad says voters should "keep the team that's working".
The ad is unusual because of the absence of Prime Minister John Key, who is usually front-and-centre in National promotions.
Campaign manager Steven Joyce said Mr Key would be in future ads.
Labour leader David Cunliffe features in all of his party's four ads, designed by Auckland agency Running With Scissors.
The ads extend the "Vote Positive" theme seen on its billboards, and politicians are mostly sidelined in favour of voters' faces.
Campaign manager David Talbot said the material was more emotional than past campaigns, without being cheesy.
Labour has also made a Maori-focused ad which will run in Maori and English on Maori Television.
National is entitled to $1.05 million worth of radio and TV advertising time this year, and Labour to $920,000.
The values are set by the Electoral Commission with a formula based on parties' votes at the previous election and other factors.