National Leader Christopher Luxon's personal support has crashed 5.6 points in the latest Taxpayers' Union-Curia poll, following his mishandling of abortion politics - although National's support remained largely steady.

Luxon polled 22.4 per cent as preferred prime minister, netting just over half the support of Prime Minister Jacinda Ardern, who scored 41.2 per cent, up 1.5 points.

David Seymour was up half a point to 6.1 per cent, trailed by former prime minister John Key on 3.7 per cent, up 1.3 points.

Commentary released with the poll suggested Luxon's personal support "dropped off after the United States Supreme Court's abortion ruling".

After the US Supreme Court overturned the constitutional right to an abortion, Luxon struggled to clearly promise National would not change abortion laws if it were in government in New Zealand. He also had to discipline MP Simon O'Connor, who celebrated the news.

National remained the most popular party on 37 per cent, down 0.4 points. Labour was up half a point to 34.7.

Act scored 10 per cent, up 0.6, and the Greens were up 0.2 points to 8.5 per cent.

Te Pati Māori surged 1.9 points to 3.7 per cent, while NZ First was up half a point to 2.8 per cent.

Other parties, likely dominated by TOP, were down 3.2 points to 3.3 per cent.

This would give National 47 seats and Act 13. They would need Te Pati Māori's five seats to form a Government.

This is unlikely as Te Pati Māori has said it would not want to be a part of a right-wing coalition, and Act is not keen on working with Te Pati Māori either.

But Te Pati Māori's support would not get an alternative Labour-Green Government over the line. Labour would win 44 seats and the Greens 11 on this poll - 55 seats in total.

With Te Pati Māori's five seats, the left would be one seat short of the 61 needed to form a government.

The cost of living and the economy were the most important issues identified by voters in the poll, followed by health and housing.

The poll was conducted between Sunday, July 3, and Sunday, July 10, 2022. The sample size was 1200 eligible New Zealand voters (800 by phone and 400 by online panel), giving the poll a margin of error of 2.8 per cent.