Prime Minister John Key looks certain to lead National to a second term after tomorrow's election - but it will be touch and go as to whether he will need support parties.

And today's Herald-DigiPoll survey shows Winston Peters' New Zealand First party is above the 5 per cent of voter support needed to put it back in Parliament.

The campaign ends tonight with Mr Key and Labour leader Phil Goff travelling up the North Island in rival buses.

The polls continue to show that the fortunes of the large parties, which have not moved significantly in the past few weeks, will rest on small movements in smaller parties.


Today's Herald-DigiPoll survey shows New Zealand First scraping over the 5 per cent threshhold. That would put leader Winston Peters back in Parliament with five other MPs after a term in exile.

Today's poll also throws up a bizarre possible outcome - National winning more than 50 per cent of the party vote but still needing Act, the Maori Party or United Future to give it a majority in Parliament.

This could happen if today's poll results were translated to votes.

The revival of New Zealand First - which National won't deal with - could make the survival of Act crucial.

The Maori Party could be in the box seat to negotiate a confidence and supply agreement to give National a cushion of comfort if Act and United Future don't make it.

The reason National could get a majority of party votes tomorrow but not a majority of seats in Parliament is the overhang factor.

If today's poll figures were translated to votes, United Future, the Maori Party and Mana would get more electorate seats than their party vote entitlement.

When that happens, the size of Parliament expands beyond 120 seats, and the parties are allowed to keep the extra seats.


In this case, the "overhang" seats would take Parliament to 126 seats.

In that scenario, a Government would need 64 seats for a majority and in today's poll, National would have 63 seats - based on the assumption that Act, Mana, United Future and the Maori Party will keep their electorate seats.

Only Act and United Future have pledged to support National.

United Future scores zero in the poll, and its sole MP, Peter Dunne, could struggle to keep the Ohariu seat.

The Maori Party says it could go either way though it would try to negotiate first with National if, as expected, it has the most seats.

If John Banks won Epsom for Act, he would bring in another MP.


But if Act lost Epsom and Mr Dunne lost Ohariu, the recalculation of seats after discounting the wasted votes would give National an outright majority, by one vote.

Likewise if the poll were recalculated with New Zealand First losing only 0.3 points to Labour, National would win an outright majority.

On today's poll, the Greens on 11.8 per cent would bring in 15 MPs, six more than they have now.

Labour on 28 per cent would end up with 34 MPs, nine fewer than at present.

National polled 50.9 per cent (up 1 point in a week), Labour 28 (down 1.1), Greens 11.8 (down 0.8), NZ First 5.2 (up 0.3), Act 1.8 (up 0.1), Conservatives 1.3 (up 0.7), Maori Party 0.4 (down 0.3), Mana 0.3 (down 0.1), United Future 0 (down 0.1).

The popularity of Mr Key as preferred Prime Minister remains high at 66.3 per cent, down slightly from 68.5.


Mr Goff's popularity has continued to rise throughout the campaign. He began it on 11.7 per cent and is now preferred Prime Minister by 19.5 per cent.

That could dampen any early challenge against his leadership, in the event of a loss.

* The poll of 850 voters was taken between November 17 and 23. The party vote figures are of decided voters only. The undecideds were 7.7 per cent.