Jacinda Ardern's rallying cry: Climate change the nuclear-free moment of her generation

Labour leader Jacinda Ardern has targeted climate change as a priority area, saying it was the "my generation's nuclear-free moment".

Ardern made the call in a speech at Labour's campaign launch - attended by more than 2000 people who filled the Town Hall, the nearby Q Theatre and still overflowed outside.

She was given a rapturous reception by newly energised party faithful at an event that included a star appearance by Helen Clark, MCing by comedian Michele A'Court, singer Hollie Smith, and an endorsement speech by party supporter Don McGlashan.

There was no new policy in her speech, but Ardern set out the areas she intended to emphasise as leader, including children and climate change.

Labour leader Jacinda Ardern says she will never stop talking about climate change, because it's the challenge that defines her generation. Photo / Michael Craig

Her speech was part rallying cry for the election campaign and part setting out her key priority parts.

In her speech, Ardern said the first time she was boo-ed in politics was at a public meeting in Matamata when asked about climate change.

"But I will never stop talking about it, because it's the challenge that defines my generation.

This is my generation's nuclear-free moment and I am determined that we will tackle it head on."

Speaking afterwards Ardern said she remained committed to long-standing Labour policy for an emissions trading scheme that covered all gases and all sectors - including agriculture.

However, she said a Labour government would legislate for carbon emissions targets to ensure they were reported.

"We need to be transparent with people about how we are progressing. I don't accept New Zealand is a country at the bottom of the world that can't play its part, particularly when we have the Pacific on our doorstep and they are so affected."

Labour leader Jacinda Arden is joined on stage by her MPs after delivering her speech at the Labour campaign launch in Auckland Town Hall today. Photo / Michael Craig

Ardern also reiterated her push to restore water quality but denied she was targeting Green Party territory.

"Any politician in 2017 needs to be talking about these issues, no matter what shade. These have always been things I've cared deeply about and to be honest I just focused on things I was passionate about."

The Green Party has plummeted in the polls from double figures to between 4 and 8 per cent since Ardern became leader and the Greens' Metiria Turei stepped down as co-leader after a welfare fraud admission.

Ardern also addressed insinuations she did not have the economic ballast to run the country, especially compared to Prime Minister Bill English.

She has not ruled out changes to income tax or a capital gains tax and said that would happen after the pre-election opening of the books by Treasury this week.

Labour leader Jacinda Arden goes walkabout after delivering her speech at the Labour campaign launch. Photo / Michael Craig

She said she would never say the economy was not important, but believed it had to be about more than numbers - and about serving people. She said housing was "a right" and Labour would add child poverty to the Public Finance Act to ensure the Government was held to account for lifting children out of poverty.

Ardern is due to make a transport announcement on Monday and said she would bring a "different vision" to that English set out on Sunday in a $10 billion announcement for new highways.