Prime Minister John Key warned voters yesterday that a new government after Saturday's election could be brought down on any issue by New Zealand First leader Winston Peters unless National won enough votes for "strong, stable, dependable leadership".
He stopped short of saying he wanted National to govern alone.
But with support partner Act in a shambles, and Mr Peters closing in on the 5 per cent threshold, it is clear National is making a coded pitch for majority government.
Mr Peters made it clear last night that New Zealand First would not do any deals with Labour or National to form a government.
Yesterday morning, Labour leader Phil Goff refused to say in a television interview if he trusted Mr Peters.
In the afternoon, he rallied Labour's foot-soldiers in Auckland with a call to arms to oppose the partial sale of state assets.
Mr Goff and Mr Key will meet tonight in a TV3 debate, the first head-to-head clash since the Press debate in the campaign's second week, when Mr Key upstaged Mr Goff over the cost of Labour's policies.
Mr Goff took a week to recover but has since run a strong campaign, bar some memory lapses on figures in television interviews.
Today, the Prime Minister will unveil National's last major policy, on education.
Mr Key has preferred to avoid the issue of Mr Peters but the spectre of the NZ First leader's return has caused National to rethink its tactics. The latest Herald-DigiPoll survey showed Mr Peters' party on 4.9 per cent and with the potential, along with the Greens and the Maori Party, to hold the balance of power.
Yesterday, Mr Key seized on weekend television interviews with Mr Peters to paint a picture of imminent instability if the votes go the wrong way for National on Saturday.
Mr Peters repeated his position that NZ First would not enter a confidence-and-supply agreement with either National or Labour.
But he also said his party might vote for Budgets and other issues case by case, and he did not have a definitive position on whether the party might abstain or not.
Said Mr Key: "What Winston Peters is saying to New Zealanders is that on every Budget, on every issue, there could be a general election. How could New Zealand govern itself over the next three years, which is likely to be a volatile period in the world economy, when at any stage the whole Government can be brought down by Winston Peters?"
Mr Key said National would provide strong, stable, dependable leadership. Mr Goff could not, the PM said, because the only way he could get into government would be with the Greens, NZ First and Mana.
An unknown in post-election permutations that could turn out to be vital is whether NZ First might abstain if that was critical to government formation. Mr Peters said that would be up to any caucus, not him.
National has kept its 2008 position of not entering into any agreements with NZ First.
Last night, Mr Peters said Mr Key should not panic even if he got the election results he didn't want. "We believe that whoever gains the largest share of the votes should try to form a government, just as previous leaders did and succeeded, and New Zealand First will always respect that principle.
"But we will not sign a blank cheque in the form of a supply-and-confidence agreement."