Ardern put it down to tough decisions she had to make to deal with Covid-19.
"I still feel really confident knowing that people know we've made those tough decisions for the right reasons.
"And, yes, that will have an impact on things like polls but it doesn't change those decisions we've made and how well they've served New Zealand."
Luxon won't be celebrating in a big way just yet. His performance in the poll was bolstered by the 37 per cent of people who either didn't know whether they approved or disapproved of him, or declined to answer.
The poll showed 42 per cent of people approving of Luxon and 20 per cent disapproving.
Another reason for Luxon not to get too comfortable is the same poll showed support for Labour a long way ahead of National, which could not form a government on these numbers.
National is on 32 per cent in the poll, trailing Labour's 40 per cent. Act scored 11 per cent, and the Greens, 9 per cent, giving the left-leaning parties the numbers to form a government.
Ardern was dragged down by results showing her to be increasingly polarising: more people both approving and disapproving of her - 52 per cent of respondents said they approved, 37 said they disapproved.
Just 10 per cent gave no answer or said they didn't know, which is probably to be expected given Ardern has been Prime Minister for four years - most people have an opinion on her.
Ardern's rating is possibly hampered by the long Delta lockdowns in Auckland and uncertainty over the future with Omicron.
She still has significant backing among Labour supporters, who give her a 90 per cent approval rating, and Wellingtonians, 65 per cent of whom approve of her.
Ardern appears to have lost support among the wavering National voters who delivered her a historical majority at the 2020 election.
The groups that are more likely than the average New Zealander to disapprove of Ardern include Pakeha, 41 per cent of whom disapprove of her, and people with a household income of more than $100,000, 46 per cent of whom disapprove of her.
Luxon's support comes from National and Act supporters, and people with household incomes of above $100,000, 57 per cent of whom support him.
He also enjoys above-average support among men aged 35-54, 56 per cent of whom support him.
He is most strongly disapproved of by Green and Labour supporters, as well as people with a household income of below $30,000, 28 per cent of whom disapprove of him.
The poll ran from Saturday, January 22 until Wednesday night and polled 1000 eligible voters. The maximum sampling error is approximately ±3.1 percentage points at the 95 per cent confidence level.
