Winston Peters' potential role as coalition kingmaker is fading as poll ratings for New Zealand First slide and as National's Bob Clarkson mounts a stern challenge against him in Tauranga.
That has the National Party contemplating a Parliament without Mr Peters and NZ First - which would deal a serious blow to Don Brash's chances of leading a government.
For National to govern, it will almost certainly need the support of NZ First. Labour may also need its support, if the Greens' fortunes fade.
Mr Peters yesterday rubbished internal National Party polling which they say puts him and Mr Clarkson neck and neck in the seat he has held since 1984.
But it comes on top of last night's One News Colmar Brunton poll in which NZ First had slipped to 5 per cent, the threshold the party would need to reach to get to Parliament if Mr Peters lost Tauranga.
An average of the last four polls still has NZ First above the cut-off, at 6.4 per cent of the party vote.
Even that is a notable slide since its double-figures polling of just three months ago. Internal party polling is notoriously difficult to rely on.
However, it is understood two polls show the high-profile Mr Clarkson has been gaining on Mr Peters for some weeks.
The pair cannot be separated in National's latest survey, conducted before last week's tax cuts announcement, and it shows no other party's candidate is a serious contender.
Mr Peters said he was not taking the National Party's word for any polling.
"I am not reacting to a National Party jack-up poll. I just work hard 24-7 and that's it.
"I have confidence in the New Zealand people and I have confidence in the electorate."
Mr Clarkson is ranked at 50 on National's list.
He would not reveal anything about the party's polling last night, but said Mr Peters had "a race on his hands, I can tell you".
Mr Peters had a 10,362 vote majority at the 2002 election.By Helen Tunnah