MMP gives power to political minnows
The most recent Roy Morgan political poll showed support for National had dipped to less than Labour and the Greens combined.
This means there is little chance of a centre-right government on current levels of support (50 vs 59 seats, Nat vs Lab/Green). The minnow parties are therefore key, as several of them may be wiped out of Parliament and thus the seats will have to be re-allocated (in the sense that the numbers based on the percentage, change).
So if United Future or Mana do not win a seat, their levels of support do not translate for them into a seat in Parliament. Of note, is that the Conservative Party are stable as the fifth highest polling party since the 2011 election, more than United Future and Mana combined (the latter was too low to register).
David Farrer (who polls for National professionally), at Kiwiblog, allocated parliamentary seats based on the Roy Morgan poll as follows, but for some reason completely omitted the Conservative Party, probably because they are not currently a parliamentary party.
Conservative 3 [omitted by Kiwiblog]
Here are the actual poll percentages with my allocation of the 120 seats based on this poll support (in brackets).
National 41.5 per cent (50) .
Labour 33.5 per cent (42).
Greens 13.5 per cent (17).
NZ First 6.5 per cent (6). Must be above 5 per cent or win an electorate.
Conservative 2.0 per cent (3). Needs to win an electorate.
Maori Party 1.5 per cent (2). Possible Parlimentary overhang.
ACT NZ 0.5 per cent (0).
United Future 0.5 per cent (0).
Others 0.5 per cent (0).
Mana 0 per cent (1). If they win a seat, possible Parlimentary overhang.
The key point here is, of the parties under 5 per cent, who holds an electorate seat (and thus their party votes count)?
Will Mana win their Maori seat?; will the Maori Party win their seats, or will NZ First win them?
It is very much in National's interests to consider talking to the Conservative Party and NZ First about a possible seat accommodation (where National might not stand against them) as their support will be critical to a centre-right coalition Government in 2014.
National has only three choices, in descending order: NZ First, Conservatives and the Maori. This would deliver a coalition government but depends on all three minnows holding at least one electorate seat.
Maori 2 (61 seats)
During the election campaign, as voters perceive small parties won't make it, their support is likely to peel off to the possibles (NZ First, Conservative, Maori). These three are likely to compete very strongly for the party vote.
MMP delivers significant power to small parties, what is known in political parlance as 'the tail wagging the dog'.
The mongrel of NZ First and the terrier of Conservative Party are therefore worth patting; but National will not court the old Lab.