A controversial issue in the election campaign was the end of a moratorium on genetic engineering, strongly opposed by the Green Party.

The release of Nicky Hager's book Seeds of Distrust prior to the election also sparked much debate.

The book examined how the government handled the contamination of a shipment of imported corn with genetically modified seeds.

The Prime Minister, Helen Clark, claimed that an early poll was necessary due to the collapse of her junior coalition partner, the Alliance.

Critics, however, claimed that Clark could have continued to govern, and that the early election was called to take advantage of Labour's strong position in the polls.

Many opinion polls for the election indicated that Labour was popular enough to conceivably win an absolute majority, leaving it able to govern without the support of smaller parties.

Once the final distribution of seats was determined, it was clear that Labour would be at the centre of the government, and that it would be allied with the Progressives.

However, this still left Labour needing support in matters of confidence and supply, as the two parties together fell short of an absolute majority.

Labour expressed a preference for an "agreement" rather than a full coalition, hoping to establish an arrangement similar to the one that existed with the Greens prior to the election.

After a period of negotiation, Labour opted to ally with United Future, being unwilling to change their genetic engineering policies to secure the Green Party's support.

However, Labour's strong position in this election led to National losing ground in a number of its traditional strongholds.