NZ Election 2020: Judith Collins 'disgusted' with Jacinda Ardern's reminder of her run-in with Serious Fraud Office

Labour leader Jacinda Ardern has made the first dig ahead of the Newshub Leaders Debate, reminding National leader Judith Collins that NZ First leader Winston Peters is not the only one that's had a run-in with the Serious Fraud Office (SFO). 

The SFO announced on Tuesday charges against two people in regards to the New Zealand First Foundation, and it said neither those charged are New Zealand First members, staffers or MPs. 

Peters is on the warpath, saying he'll take the SFO to court over unfairly scrutinising the New Zealand First Foundation over other political parties under investigation. 

Collins told The AM Show on Wednesday it "looked like the end of his political career", but Peters says he'd be "more worried about her career than mine". 

Peters doubled down on his warpath on Wednesday claiming NZ First had been singled out and treated unfairly by the SFO. 

"They put us through months and months of hell," he said. 

Peters is trying to regain traction in a campaign that looked to have him out on his ear. The party was on 1.5 percent in Newshub's latest poll. 

Perhaps craving more attention, Peters has pulled a spectacular U-turn and decided to appear in Newshub Nation's minor party debate on Thursday. 

But first, the clash of the titans is on Wednesday night between Ardern and Collins in the Newshub Leaders Debate, and the stage is set both physically and mentally.

Collins announced on Tuesday she'd double the funding of the SFO, and Ardern hit her with a throwback burn.

"There's obviously a little history there with the Opposition leader and the SFO," Ardern said. "As a previous minister her engagement with the SFO led to her job loss."

In 2014 Collins was forced to resign after accusations she was involved in a smear campaign against former SFO boss Adam Feeley. An investigation cleared her. But it's a sore spot for Collins, and Ardern hit her where she hurts.

"I was disgusted with that response from her and clearly she is wrong," Collins told Newstalk ZB. 

In their last debate, the Labour leader backed away from a scrap, saying she doesn't think of it as "bloodsport". 

Collins later responded, "Oh, poor wee thing."

Now it's time for round two so let's get ready to rumble.