The latest Taxpayers' Union-Curia poll shows Labour's Chris Hipkins has overtaken Luxon as preferred Prime Minister for the first time since the last election, although by a tiny margin.
The poll also shows the centre left bloc - Labour, the Greens and the Maori Party - would just be able to form a government, with 61 seats.
The poll - conducted last week - gives the centre-right bloc just 58 seats - not enough to form a government
The Taxpayers Union says the poll is a wake-up call for Luxon, and the country needs to see a plan to rebuild the economy.
Speaking to RNZ's First Up, Willis shrugged off the result, saying there are always plenty of polls between elections.
She said the government was focused on easing the cost of living by delivering economic growth that ensures people can earn more.
Asked if Luxon will still be leader at the next election, Willis gave an emphatic yes.
The prime minister played down the latest results, saying polls were "bouncing around a lot".
On Monday, Luxon said he was focused on Kiwis - not the polls.
He said it was a "tough time for Kiwis" and the government's job was to focus on what New Zealanders want, and "that is all about us fixing the economy".
"It has been a really tough time, but I think there are signs the economy is improving, but ultimately people need to see it and feel it," he says.
Luxon says there are signs of the economy improving - pointing to the tourism, agriculture and manufacturing and services sectors.
