New Zealand First leader Winston Peters has lashed out at the Green Party's plans to tackle poverty with a wealth tax.

The Deputy Prime Minister took to Twitter last night to call out the Green's new policy announcement.

"The Greens wanting to tax Kiwis an 'envy tax' to implement a 'guaranteed minimum income' is nuts. As Churchill correctly once said 'for a nation to try to tax itself into prosperity is like a man standing in a bucket and trying to lift himself up by the handle'."

Prime Minister Jacinda Ardern was also dismissive of the Greens' new tax proposal, telling RNZ it included some "fairly heroic assumptions".


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Yesterday the Greens unveiled its first major election policy, which would tax the wealthy more to fund a payment of at least $325 a week for anyone not in fulltime work.

A wealth tax of 1 per cent would apply to "net assets worth over $1 million" and 2 per cent for net assets over $2m. These would only apply to the value above those thresholds and would discount the value of, for example, mortgages held by landlords owning a suite of rental properties.

The Greens also want a 37 per cent tax rate for earnings over $100,000 a year, and 42 per cent for earnings over $150,000. The top tax rate is currently 33 cents and applies to all income above $70,000 a year.

Green Party co-leader Marama Davidson said this morning that the policy was a priority but wouldn't say if it might be a bottom line in any post-election coalition negotiations.

She said older people or retirees who had assets but lacked cash could defer payments.

"We understand that many older people may have a home, for example, worth more than $1m and it is paid off, they don't have a mortgage, but perhaps they're living on Super or perhaps they're moving to a retirement home and wish to put their home into a trust - you can defer payments," she told RNZ.

"The trust also is liable for a wealth tax, but again, it is shared among all beneficiaries and trustees, so again only if each individual has more than $1m net wealth worth then we are asking them to chip in at 1 per cent over and above that $1m."


National's finance spokesman Paul Goldsmith was opposed to the proposals.

"Our simple view is that at a time when our economy is going down, we don't need more taxes," he told RNZ.

"Every society wants to be able to help those in need the most, and the best way to do that is to create jobs and provide jobs for people to work and those jobs require investment."