With little movement this week's poll, we look at bottom-lines and why New Zealand First seems to be anchored at around three percent

I've just updated our PollWatch Poll of Polls and there's no change in the number of seats each party is likely to hold after the election.

On the face of it, Labour must be a little worried at the apparent lack of momentum with only four weeks to go when most of the most recent polls were taken. On the other hand, each of the polls in the past few weeks shows the gap either stable or closing, so any momentum that exists seems to be with them. But then, on the other hand, it may be that Labour got some momentum from its campaign launch and bank deposit promise only to see it fade after the debate. On the other hand... yeah, let's just agree that the polls are volatile.

The potential coalition deals are much less so, however. In fact, we're probably clearer on who might go with whom after the election than we've ever been since MMP began. The Dominion Post has laid out a helpful list of bottom-lines:

National will not work with NZ First.

National has ruled out having ACT's Roger Douglas in the Cabinet, should the parties strike a coalition deal.

Labour leader Helen Clark said she would not work with National, and probably not ACT.

The Green Party will not form a government with National.

UnitedFuture leader Peter Dunne has said his party has no bottom lines.

For some reason the paper left out the fact that the Progressives have committed to Labour and Act to National. The only swing parties left are the Maori Party and the oft-forgotten United Future.

What it all means is that the centre-right grouping of National and Act have 63 seats under our Poll of Polls, while the centre-left grouping of Labour, the Greens, and the Progressives, have 53. As Colin James points out in the Herald today, the overhang could make for a parliament with as many as 124 MPs. That leaves National, Act, and possibly United Future with enough seats to govern. Just. But if the polls are closing a little, if Labour and the Greens have a couple more seats as some polls suggest, then it's neck and neck.

If New Zealand First gets back to five percent, then the seats are redistributed and the equation changes again–in Labour's favour. But it's interesting to note their lack of poll movement over the past few weeks. There has been talk of a Winston come-back, drawing on the logic that he'd done it before, that he's a great campaigner, that some people felt he was picked on over the Owen Glenn donation story. But the numbers just aren't showing that. He's anchored at between three and 3.5 percent. He doesn't seem to be getting the old people off National or the Maori off the Maori Party, which is what he needs. Not yet, anyway.

Why? Perhaps his blue-rinsed supporters care about donations and process and ethics, or perhaps they (and their conservative instincts) have been caught up in the swing back to National over the past year or so. Perhaps his Maori supporters see more bang for their buck in the Maori Party these days. Giving sympathy is one thing, giving your vote is quite another, especially when there are so many other viable options on the table in this election.

Then, of course, there's the Maori Party. We're assuming it wins five seats. We think Nanaia Mahuta will hold Hauraki-Waikato and in Ikaroa-Rawhiti, who the heck knows? Other polls of polls are picking it wins six. Some commentators are picking seven.

So all we can say with certainty is that there's plenty of time left for voters to have a re-think and for the undecideds to be won over.