Poll of Polls - Nationals ratings have trended down in the first five months of this year and Winston Peters holds the balance of power.

Photo: RNZ / Rebekah Parsons-King

National was averaging 48.0 percent at the beginning of the year. The May average was 45.3 percent. That is not enough to form a government with its three current mini-partners, the Māori party, ACT and United Future. It was 3 percentage below its 48.2 percent average in May 2014.

From its May 2014 standing, National climbed to a peak of 52.5 percent in mid-July, from which it dropped to 47 percent in the election in September.

Also in May 2014, National's lead over the Labour and Green parties combined was 6.0 percent, climbing to 14.7 percent in mid-July. The lead this May was 4.1 percent and the trend has been fairly steadily down through the year.

Labour's May average was a still torpid 29.4 percent - the bounce after electing Jacinda Ardern as deputy leader did not push it higher.

The Greens were at 11.9 percent. These figures are both within a whisker of where they were in May 2014.

New Zealand First was 9.4 percent, well above its 5.1 percent in May 2014. The smaller parties were all around or below 1 percent. The Māori party was 1.6 percent (2.1 percent if Mana's support is added in), ACT 0.9 percent, the Conservatives and Opportunity party at 0.7 percent and United Future at 0.1 percent.

Assuming the Māori party, ACT and United Future win electorate seats, the makeup of Parliament on the May ratings would be 55 National plus two Māori party and one each for ACT and United Future - a total of 59 seats, just short of a majority.

Labour would get 36 seats and the Greens 15.

In this scenario New Zealand First, with 11 seats, would hold the balance of power.

Good news for National is a continuing strongly positive view of whether New Zealand is on the right or wrong track.

In the UMR poll in late May 60 percent were positive and only 30 percent negative.

* The poll-of-polls is an arithmetical average of the four most recent major polls from among: TV1 Colmar Brunton, TV3 Reid Research, Roy Morgan New Zealand plus the unpublished UMR Research (for the Labour party) and Curia (for the National party). The latest average is from, in chronological order, Morgan, Curia, UMR, TV1. The first point on the charts is the actual 2014 election result. Only Roy Morgan, UMR and Curia have polled in every month since the election and Curia has been included only since September 2016. In the past, polls for the New Zealand Herald and Dominion Post were included, but these have been discontinued. UMR has given permission to use its right track-wrong track figures.