"I am ready. We're all ready. Let's do this."
But National has hit back with a Facebook ad captioned #LetsTaxThis, saying Labour "needs to be upfront with NZers about their tax agenda".
It plays a scratchy recording of Labour's housing spokesman Phil Twyford listing taxes that would be "on the table" in a Labour Government's first term, including a capital gains tax, asset taxes, wealth taxes and a land value tax.
What is Labour's tax policy?Labour needs to be upfront with NZers about their tax agenda. A senior Labour MP has admitted: “A Capital Gains Tax will be on the table, Land Value Tax will be on the table, Asset and Wealth Taxes.” #LetsTaxThis
Posted by New Zealand National Party on Monday, 21 August 2017
In his speech on August 10 he also says it's a "tough ask" to sell a capital gains tax while in Opposition.
"It's much easier when you have an army of public servants when you're in Government and you have a much bigger megaphone."
National has also taken aim at the Labour leader's philosophy of "relentless positivity" on its website, claiming a Labour/Greens/NZFirst coalition would have a "relentlessly negative view of New Zealand".
This month on Newshub's The Nation Steven Joyce pounced when Labour finance spokesman Grant Robertson did not say outright if a capital gains tax would be introduced by a first-term Labour government.
He did say that the "bright-line test", which taxes income on property bought and sold within two years - would be extended to five years under Labour.
Ardern has since clarified that under Labour a capital gains tax would only come from realised gains - money made when an asset is sold - and the family home would be exempt.
The Labour leader told the Herald today she would also not make a call on raising the top income tax rate until the Treasury opens the Government's books tomorrow in the Pre-election Economic and Fiscal Update.