National Party leader Judith Collins has sent a warning to Prime Minister Jacinda Ardern after comments she made regarding Collins' past with the Serious Fraud Office.
Speaking to Newstalk ZB's Kate Hawkesby this morning, the Opposition leader was asked whether she thought Ardern might be "upping the sass" in tonight's Newshub leaders' debate.
"Well I tell you what - she better not do that," Collins said.
"I've asked her to come back from what she said and to obviously correct the record - because what she said yesterday was absolutely untrue."
Collins was referring to comments made by the PM after National announced yesterday that, if elected, it would be doubling the SFO's budget from $12.7 million a year, to $25m.
Ardern took a jab at the move, referring to Collins' resignation from a ministerial post six years due to an engagement with the SFO.
Ardern said it was interesting to hear.
"There's obviously a little history there with the Opposition leader and the SFO - as a previous minister, her engagement with the SFO led to her job loss," the PM said.
Collins, once the minister responsible for the SFO, resigned that and other ministerial portfolios in the lead-up to the 2014 election, after an email emerged that appeared to link her to a blog campaign to undermine former SFO boss Adam Feeley.
Then PM John Key initiated an inquiry, which found that while Collins had provided information about Feeley to WhaleOil blogger Cameron Slater, "there was nothing improper about the provision of this information".
Collins acknowledged today she was not happy with the comments and was calling on Ardern to retract them.
"She's in a position of Prime Minister - that's really bad," she told Hawkesby.
"So I expect she'll want to distance herself from those comments today."
Tonight's Newshub leaders' debate will kick off at 7.30pm.