'It clearly is damaging' - 1 NEWS' Corin Dann on the growing criticism of Labour's uncertain tax plans

Winston Peters' demands that Labour reveal any possible land tax policy before the election has created "damaging" uncertainty around a potential Ardern Government, 1 NEWS political editor Corin Dann says.

1 NEWS' political editor says it's hard for Jacinda Ardern to defend their current stance. Source: 1 NEWS

The New Zealand First leader has called for Labour to release all its tax policy ahead of the election and not hide behind a tax expert committee which Labour intends to commission.

Read more: 'We've put it all out there' – Jacinda Ardern defiant over Winston Peters' calls to reveal tax plan

Labour says it will not commit to all their tax policy before this committee has properly investigated and reported back.

The NZ First leader says Jacinda Ardern needs to be more upfront about her party's plans. Source: 1 NEWS

"It clearly is damaging, and it's not helpful to have Winston Peters jumping on board, echoing National's criticisms," Dann said. 

"The problem for Labour is not so much the capital gains tax, we saw in our poll 58 per cent support that as long as it's not on the family home.

"But it's the ability of National to raise other possible taxes which Labour's not willing to rule out from that committee, so that's the problem for them.

"But I think there's also a bit of strategy going on here from Winston Peters, he's also positioning himself perhaps with soft Labour voters who are wavering a little bit signaling that he could be some sort of potentially moderating force on a future Labour government. So maybe a bit of strategy at play." 

Mr Peters was of the opinion that because Labour has ruled out a capital gains tax on the family home, they necessarily also knew which taxes they had ruled in.

The Labour leader has repeatedly said she will employ a tax working group to help make policy if elected. Source: 1 NEWS

"Usually people want disclose good things and hide bad things, I just want to know, and I think the tax payer should know, before they vote," Mr Peters said.

Jacinda Arden said Ms Peters has "wrongly implied" Labour has worked through "all of our [tax] expectations and we haven't".