New Zealand's governing Labour Party has lost some support since July as the coronavirus resurged in Auckland, but it is still set to win the upcoming general election on October 17 comfortably, an opinion poll has shown.

The 1News-Colmar Brunton poll on Tuesday showed support for Prime Minister Jacinda Ardern's party, which is seeking a second term in office, at 48 percent, down 5 percentage points since the last poll in late July.

The main opposition National Party also lost 1 percentage point taking it to 31 percent, under newly elected leader Judith Collins.

The results mean Labour could get 62 seats and would be able to govern alone without any coalition.

Small parties such as the Green Party got 6 percent support while the ACT New Zealand surprised with 7 percent support.

But populist New Zealand First Party, a kingmaker in the last election, dropped to 2 percent, which means it would not get into parliament if it does not win an electorate seat.

All recent polls have pointed to a comfortable victory for Ardern, who has won global praise for her leadership during the pandemic.

The 40-year-old, who became the world's youngest female leader after unexpectedly winning power in 2017, holds huge appeal domestically and globally where she has garnered praise for her views on issues such as women's rights, climate change and diversity.

Ardern has also won international praise for her empathetic and decisive response to last year's attack on two Christchurch mosques by a white supremacist, in which 51 Muslim worshippers were killed.

The leader also implemented tough lockdowns when then the coronavirus pandemic erupted, which health experts say has helped contain the virus.

In the first televised debate before the vote on Tuesday, Ardern said she stood by her coronavirus programme that has limited the outbreak's toll to 25 deaths in a population of 5 million.

"I know there is a huge amount of uncertainty right now. That's why a plan is necessary, so is optimism; that's what Labour will bring," she said.

Collins, 61, said Ardern's government had failed to secure New Zealand's borders.

Ardern has called it a "COVID election" and focused her campaign on highlighting the government's success in tackling the health and economic challenges thrown up by the pandemic.

Ardern's stardom, however, masks some of the domestic issues that the ruling coalition has failed to tackle, including a shortage of affordable housing, child poverty, and tax reforms.

Collins, popularly known as "Crusher Collins", became National Party's third leader this year and has promised massive infrastructure spending, reduced taxes and a boost to the economy.