Attention has turned to infrastructure this week in an election campaign that seems increasingly likely to change the government on October 14.
A Roy Morgan poll on Tuesday showed Labour sinking to 26 per cent - the lowest level so far this year.
Centre-right opposition National is on the rise, up to 33.5 per cent, and able to govern with coalition partner ACT, right-wing libertarians.
On Monday, National released their $NZ24 billion ($A22 billion) infrastructure plan, centred around 13 new "roads of national significance".
Around $NZ10 billion ($A9 billion) could come from private investment, with a National Infrastructure Agency would "connect domestic and offshore investors" with the projects.
"There's a lot of pension funds, there's a lot of sovereign wealth funds that want to invest in infrastructure for long term returns," Mr Luxon told TVNZ.
"We can be using private capital and alternative funding mechanisms (as) a strong and resilient roading network will be absolutely critical to our future."
He said China's infrastructure investment vehicle would "absolutely" be welcomed to build the roads.
Mr Luxon also bit back at TVNZ's Breakfast host who suggested China might seek to impose similar conditions for infrastructure projects in the Pacific, including bringing their own workers or tough repayment schedules.
"That's not going to happen," he said.
"That's quite a xenophobic sort of response and a pretty simplistic response."
Under the last National-led government, New Zealand signed a "memorandum of arrangement" that would underpin Belt and Road projects, however, it has not yet led to any investment.
ACT leader David Seymour came out against National's plan.
"We can't follow the lead of Pacific nations who have accepted investment from China, only to find they're now in serious debt to a communist regime flexing its muscles," he said.
"We need to welcome foreign investment, but not at the cost of being bullied or cowed by a bigger nation looking to gain leverage."
Mr Luxon has also faced criticism for the roading plan as it would fall foul of New Zealand's legislated emissions budget reductions.
While insisting he would meet New Zealand's net zero target by 2050, the National leader said the priority for the national transport agency should be "improving convenience for people moving around our country".
"We can have great roads and we can also deliver on our climate goals," he said.
National's plan also shone a light on Labour's record on infrastructure during its six years in office.
One of Jacinda Ardern's flagship projects - light rail from Auckland's CBD to the airport - remains in a planning phase, while an infrastructure plan for the capital - Let's Get Wellington Moving - appears set to be junked.
Prime Minister Chris Hipkins said he didn't think the Wellington plan "has delivered what it was set up to deliver", foreshadowing a change in policy in the party's yet-to-be-released manifesto.
