The Opportunities Party leader Gareth Morgan says he doesn't need to apologise to Labour Party leader Jacinda Ardern over his 'lipstick on a pig' tweet because it was not a personal attack.
Mr Morgan made the comments on Twitter this morning, implying that fronting the party with a new face does not change their underlying policies.
"Jacinda should be required to show she's more than lipstick on a pig. Will she be?"
He then went on to tweet a photo of a pottery mug resembling former National prime minister Robert Muldoon, with a stick of lipstick next to it captioned: "Policy matters".
"Hero worship from Jacindaphiles pathetic, policy PSE," he wrote.
"Jacindaphiles need to remember substance matters - let's see credible policy."
At a press conference today, he faced questions over the tweets, but stuck to his guns and said he would not be apologising.
"I'm not apologising because I'm talking about the Labour Party here and the Labour government - I'm not talking about Jacinda," he said.
He said he would have "totally" used the same idiom, made popular by Barack Obama in 2008, if the politician had been a male.
"The pig is the actual establishment party and that's what the metaphor means," Mr Morgan said.
"I could have said something far more Gareth Morgan - like it's the same as polishing a turd - same point.
"In so far as Labour does not come up with policy of substance, that's exactly what they're doing.
"While shes obviously got communication skills ... she's got to have content ... there's nothing to apologise to her for."
The recent 1 NEWS Colmar Brunton poll put Labour up 13 points at 37 per cent, the highest result since 2008, while The Opportunities Party was steady at two per cent.