Judith Collins says a Labour-led Government could put in a wealth tax if Jacinda Ardern has to take time off again.
Labour has repeatedly said a wealth tax, as proposed by the Greens, is off the table in any coalition negotiations.
"I consider that the last roll of the misinformation dice," Labour leader Jacinda Ardern said at the weekend. "Any suggestion of picking up other parties' plans is mischievous and wrong."
The Greens want to redirect money towards low-income earners by introducing new income tax brackets and a wealth tax on assets over $1 million, excluding housing wealth under mortgage and "normal household goods" up to the value of $50,000.
The Greens say the latter would only affect 6 percent of New Zealanders, and is needed to stop the rich constantly getting richer by leveraging their assets - something everyday Kiwis can't do.
Collins, National Party leader, told The AM Show on Wednesday she doesn't believe Ardern.
"We know she actually wants a capital gains tax. She's said that so many times, and she's continued to say that's what her preference would be."
Ardern in 2019 ruled out introducing a capital gains tax while she's Prime Minister, "not because I don't believe in it, but because I don't believe New Zealand does".
But what if she's not leader? With her polling it's unlikely anyone in Labour would dream of pulling a Todd Muller and rolling her, but during her first term she spent six weeks out of the Beehive to give birth. New Zealand First leader Winston Peters was Acting Prime Minister in her absence. Labour deputy leader Kelvin Davis has also stood up when required.
Peters got the Deputy Prime Minister role as part of New Zealand First's coalition deal with Labour. According to the polls, he's likely not going to be in the same position after this weekend's vote, but Green Party co-leader James Shaw just might be.
"It depends on the numbers, it depends on the shape of the agreement that we've got, it depends on the extent to which we think it can help us to advance the programme of work that we have," he told RNZ in September. "It's not out of the realm of possibility."
Collins hinted Shaw might override Ardern's promise if she was away.
"What if she's for some reason not the Prime Minister, or she's got an Acting Prime Minister for a period of time - what's going to happen if James Shaw is the Acting Prime Minister? They don't oppose it. You know that they absolutely want this."
Shaw couldn't do this himself - he'd still need the backing of the majority of MPs in Parliament, most of whom are likely to be Labour, and likely still loyal to Ardern.
"Judith Collins is lying," Shaw told Newshub. "Changes to tax law have to pass through Cabinet and Parliament. The notion that an acting PM could unilaterally change tax law is utterly absurd."
Collins also claimed the Greens might not give Labour the numbers, calling the wealth tax a "bottom line" for the party. The Greens have denied this - calling it a "top priority" rather than a bottom line. Green MP Julie Anne Genter did call it a bottom line once in mid-September, but Shaw later said she misspoke.
One of the Greens' candidates, Ricardo Menéndez, has been talking up pushing for the wealth tax should the Greens be in a strong position after the election, saying Labour can't unilaterally rule it out if they need the Greens' help to form a Government. Collins has name-checked him on social media and did again on The AM Show, saying he'll "probably be in" if the Greens don't fall below the 5 percent threshold.
At 10th on the Green Party list, Menéndez will only make it in if they get at least 7.5 percent - above where the party is currently polling.
National is facing its worst election result since 2002, based on the polls. Collins doesn't appear to have any plans to relinquish the leadership should the party lose, despite once saying 35 percent was the cutoff point for resignation.
"I'm sure there are plenty of people who want that job, but I tell you what - it's mine."
She said the lockdowns to prevent the spread of COVID-19 have been "unfair" to the party.
"There's no point complaining about it - you just get on and do your best. I tell you what - we're doing really well and I feel very good about Saturday. I think we'll win."