National Party leader Chris Luxon is not going to make clear to voters what trade-offs his party might be prepared to make during post-election negotiations, or specify any "no-go" policy areas, beyond what's already been indicated.
Polling continues to show National in a favourable position to form a government with ACT, and in some scenarios needing New Zealand First as well, which begs the question - what would National be prepared to give up, or adopt, to take power?
"I'm not getting into post-election negotiations, that's not something we're going to do via the media on this side of the election," he told reporters this week, during an exchange about whether National would amend key policies like its tax plan if it meant getting a deal over the line.
"We will work with our coalition partner if we need to on the other side of the election to make sure we get strong, stable government," Luxon said.
When pushed about whether he would adopt any part of ACT's tax policy he said "no, I like National's tax plan". However, he then refused to specify any carve-outs, or policies that would be off the table during any post-election talks.
ACT leader David Seymour questions whether National's tax package as laid out now would be affordable, concluding "it's actually going to be the circumstances rather than the parties that dictate where we go".
It was up to National to release its fiscal plan, he said, but the "financial situation New Zealand faces is serious" and the picture may well be a lot worse by the time parties start negotiations after the 14 October election.
"If we are forming a government, it might go beyond what any particular party wants, it might be about what New Zealand can afford. The circumstances will mean that more is up for grabs than perhaps people realise ... but our view is, we're not going to negotiate through the media with each other.
"We have a strong personal relationship. We have clear professional differences. We're gonna work through those together if the people choose us to govern."
Luxon has already ruled out parts of ACT's policy platform, including scrapping the Zero Carbon Act; he said National was committed to the legislated climate change targets, but had a different plan from Labour to get there.
Seymour said it was the detail below the headline policy of getting rid of the legislation where the real changes could be made.
"Within the auspices of the Zero Carbon Act, you still, I think, have to make some substantial differences and changes to policy, and if you listen to what Chris Luxon is saying, using the ETS [Emissions Trading Scheme] to do the heavy lifting, he's not actually that far off us if you listen carefully to his positions."
Luxon has also ruled out any asset sales, full or partial, as well as describing ACT's treaty policy as "divisive" - but did not go as far as taking it completely off the table.
He said on Thursday he would release National's full fiscal plan "in the next week" but its tax plan "stands alone from our fiscal plan" - signalling there would be no change to the tax package already released.
In this week's 1News Verian poll, 82 percent of those surveyed said they thought "political parties should be upfront about coalition agreements prior to the election". Ten percent said "no" and eight percent said they did not know or refused to answer.
Luxon continues to keep open the option of working with Winston Peters and New Zealand First, a tactical decision in case the numbers do not deliver his party and ACT a clear path to power. A third party could also give National another option during any talks to lessen ACT's leverage, although a partnership with ACT is clearly Luxon's preference.
He is asked on an almost daily basis why he refuses to rule out New Zealand First - a party and its leader who have been criticised by National in the past; questions that become ever more relevant as New Zealand First is now registering at or close to the crucial five per cent party vote in political polls.
"I am only focused on maximising the National Party vote and making sure people understand what's at risk this election," Luxon said earlier this week.
"MMP is a system that New Zealanders have voted for now two or three times...and then I have to form my coalition government on the other side of that."
His preference was for National to work with ACT alone, and that could be done in a "very constructive way".
"I am not thinking about New Zealand First, they're not a consideration and at the end of the day I have to make a government work on the other side of the election," Luxon said.
"But as you've seen in many, many polls for many, many months and in our own internal numbers...we are able to form a government as National with support from ACT."