National Party leader John Key campaigned in four North Island centres on the eve of the election, facing a rowdy meeting disrupted by Labour supporters in Palmerston North.
Mr Key ended his campaign with visits to four Auckland electorates, and a rally in Auckland of about 300 party faithful on Friday evening, after flying from Wellington to Palmerston North and New Plymouth during the day.
In a repeat of events in Christchurch a day earlier, his supporters clashed with Labour protesters in Palmerston North.
Mr Key said Labour is clearly worried about the strength of National's campaign.
Five polls released within 24 hours put the National Party in front by at least seven points, but Mr Key said he was not taking anything for granted.
"I know in my heart of hearts I'm totally ready to do that job and it would be an enormous privilege to be Prime Minister, but in the end the voters have got to speak and I wouldn't want to be presumptive enough to get ahead of them."