Poll shock: Winston within a whisker

Winston Peters has been making political capital from the Banks-Key taped conversation controversy. Photo / Natalie Slade

New Zealand First leader Winston Peters is rising from the political grave and is within a whisker of returning to Parliament and possibly holding the balance of power.

The latest Herald-DigiPoll survey shows his party on 4.9 per cent support, just short of the 5 per cent threshold required to have MPs in Parliament without winning an electorate seat.

The 1.2 percentage-point jump gives the party its highest rating this election campaign.

If the poll were translated into votes, New Zealand First would not be in Parliament and National would be able to just govern on its own, with a small cushion of two votes from Act and one from United Future - assuming the Maori Party, United Future and Mana keep their seats.

But in a horror scenario for National - and one that is not far-fetched - small movements in numbers could have big consequences.

The poll shows the number of undecided voters is up to 12.7 per cent.

If Labour lost just 0.1 per cent to New Zealand First, and Act lost Epsom, Act would be out of Parliament, and National and United Future would not have a majority.

Mr Peters would return to Parliament leading a team of six MPs, including former North Shore Mayor Andrew Williams and former TV weatherman Brendan Horan.

If Mr Peters kept his word - given on November 6 - not to support National or Labour, then National and United Future could govern with 62 votes - five more than the 57 Labour could muster with the Greens, the Maori Party and Mana.

But if Mr Peters broke his word, Labour would be able to form a Government with the support of New Zealand First, the Greens, the Maori Party and Mana - although Labour leader Phil Goff has said he would not work with Mana.

Then, National would need the support (or abstention) of the Maori Party, the Greens or New Zealand First to be confident of the numbers to govern.

The Maori Party could be the party with the balance of power if the Greens and New Zealand First opposed National on confidence and supply.

In September 2005, Mr Peters said in a speech that New Zealand First would not be part of any coalition government, that he did not care about the "baubles" of office, and that his party would sit on the cross benches and give confidence-and-supply support to the largest party.

It subsequently entered a confidence-and-supply deal with Labour under which Mr Peters became Foreign Minister.

He and New Zealand First were voted out in 2008 after two donations scandals.

Labour's election policy to gradually lift the superannuation age from 65 to 67 may have contributed to Mr Peters' earlier rise in the polls.

But since Sunday he has made daily capital over the recording of a conversation between Prime Minister John Key and Act Epsom candidate John Banks a week ago, the subject of a complaint by Mr Key to the police.

Support for most other parties in the poll remained steady over the past week, with National on 49.89 per cent (up 0.4), Labour 29.1 (up 0.4), Greens 12.6 (no change), Act 1.7 (up 0.2), Maori Party 0.7 (up 0.2), Conservatives 0.6 (down 0.4), Mana Party 0.4 (down 0.4), and United Future 0.1 (down 0.6).

Support for Mr Peters as preferred prime minister is up from 4.3 per cent to 5.5 per cent.

* The poll of 750 voters was taken between last Thursday and Wednesday this week. The party vote figure is of decided voters and 12.7 per cent of respondents were undecided.

The poll has a margin of error of 3.6 per cent.