NZ Election 2020: Jacinda Ardern fires at John Key, Bill English's records at Labour campaign launch

Jacinda Ardern has fired a scathing broadside at John Key and Bill English's records in power, saying they left too many Kiwis homeless and in poor mental health and too many waterways polluted.

Kicking off the Labour Party's bid for a second term in power, the current Prime Minister listed where she thought her predecessors had failed.

"After nine years there was a realisation that some really important things had been neglected, and that doing things differently wasn't only possible, it was necessary," Ardern said.

"John Key and Bill English, they were good managers of our economy. And I want to thank them for that. They helped New Zealand through the GFC and they paid down debt.

"But after nine years of a singular focus on GDP and surplus, the actual result was too many families sleeping in cars, too many New Zealanders suffering from poor mental health and too many of our waterways polluted.

"I maintain the point I have often made through this term, economic growth accompanied by worsening social outcomes is not success at all. It is failure."

Ardern catalogued areas the Government had invested in and programmes that had been extended, including the Best Start Payment, the Winter Energy Payment, along with increases to benefits, paid parental leave and the minimum wage.

"We have undertaken the largest house building programme of any Government since the 1970s, with 18,000 state houses to be delivered by 2024," she said.

"We made the biggest investment in mental health ever seen in New Zealand with new, free, frontline services being rolled out around the country."

"We worked with farmers and environmental groups on freshwater reforms and invested in riparian planting, fencing of waterways and sediment control."

But Ardern also admitted her Government hadn't always met its goals and there were "lessons for us in that".

"Despite the many things we have done, we haven't always reached every goal," she told her audience.

"We wanted more homes for first home buyers. We wanted light rail in Auckland. But we've had to accept that sometimes when you try things that have never been done before, you won't always succeed, but that doesn't mean you should give up."