John Key remains well ahead of new Labour leader David Cunliffe as preferred Prime Minister, a new poll shows.

A poll by TV One programme Q+A showed Mr Key on 42 per cent, up 1 percentage point, while Mr Cunliffe was on 12 per cent, up 10 points.

NZ First leader Winston Peters was unchanged on 4 per cent, and Greens leader Russel Norman was also unchanged on 3 per cent.

The poll sampled 1000 eligible voters between September 14 and 18, and has a margin of error of plus or minus 3.1 per cent.


Mr Cunliffe told the programme it was a "pretty good start but there's more work to do."

Asked how he and deputy David Parker appealed to a diverse Labour base, he said: "We may be pale, we may be male, but I promise you we're not going to be stale.

"We are going to be part of a dynamic team, it'll be a diverse team and we're going to be going for it."

Mr Cunliffe said it was no accident that his deputy leader was also finance spokesperson and would lead a strengthened economic team.

"He will face off and he will beat Bill English."

Asked why Jacinda Ardern had not been selected as deputy leader, Mr Cunliffe said she had been considered for the job.

"Well she could do that job, she is a very able colleague, I'm sure you will see her somewhere in our top line-up, and I'm sure she has a big future in politics," he said.

"I looked at a lot of combinations and that was one of them, just as I had a long conversation with Grant Robertson about how we could use his incredible talent as well.

"But I made a decision that in the end that Labour needed a deputy who could anchor us on the economic and financial side."

Labour would be increasing the number of women in its senior line-up, he said.

Mr Parker said Mr Cunliffe was right to focus on the economy in his shadow cabinet reshuffle.

"Labour had a proud record of nine surpluses compared to the current government with four deficits in a row.

"We're determined to show that we're ready for government, and that the public of New Zealand can trust us on the economy," he said.

Mr Parker said he was from the "Presbyterian south" and could be trusted as a safe pair hands. "I'm not going to break the bank."

Political commentator Matt McCarten said the poll was a good result for Mr Cunliffe, but it would take time for him to make a significant break-through as leader.

Dr Claire Robinson from Massey University said Mr Cunliffe needed to "pull something out of the bag that we haven't seen before."

"That's going to be very difficult for him because he has been around for a while, and its hard to see what he's going to pull out of his pocket."

She said the Labour leadership team were presenting themselves as an economically competent team and an alternative government, but that was at odds with Mr Cunliffe's campaign message.

"On the one hand they're trying to appeal to the soft Labour voter that's moved to National, but on the other hand they people that they really have to shore up are the core Labour voters who are floating around, many of whom are sitting with the Greens."